Remediation of fluoride contaminated soil with nano-hydroxyapatite amendment: Response of soil fluoride bioavailability and microbial communities.

Nano-hydroxyapatite (NHAP), possessing high defluoridation capacity, has been widely used to remove fluoride (F) from polluted water, but little is known about how it affects the bioavailability and toxicity of soil F towards plants. Here, the impact of NHAP (2% w/w) amendment on immobilization, speciation and accumulation of F was studied in a soil-plant system. The results revealed that the NHAP amendment worked effectively to reduce levels of water-soluble F (37.3%-87.8%) and increase available P (76.6%-147%). X-ray photoelectron spectroscopy analysis indicated that the formation of insoluble CaF2 and the ion exchange of F- with OH- into NHAP might be involved in the mechanism of F immobilization and soil pH elevation. Exposure to NHAP significantly decreased the abundance of Cyanobacteria in tested soils, and Gemmatimonadetes abundance in bulk soil was significantly higher than that in rhizosphere soil at 1,000 mg kg-1 F spiked level. Additionally, NHAP amendment decreased F accumulation in wheat shoots (9.10%-18.7%) and roots (3.88%-22.4%), which could mainly be attributed to the reduction of soil bioavailable F and the supplement of Ca from NHAP. These results suggest that NHAP could be a promising amendment to be applied to acidic soil contaminated with F.

Efficacy of ginkgo biloba extract as augmentation of venlafaxine in treating post-stroke depression.

BACKGROUND: Post-stroke depression (PSD) is one of the most common psychiatric diseases afflicting stroke survivors. This study was conducted to assess the efficacy of ginkgo biloba extract as augmentation of venlafaxine in treating PSD. METHODS: The included PSD patients were randomly assigned into the experiment group (receiving ginkgo biloba extract plus venlafaxine) and control group (receiving venlafaxine alone). The treatment was continued for eight weeks. The Hamilton Depression Rating Scale (HDRS) and the Self-rating Depression Scale (SDS) were used to assess the depressive symptoms. The National Institutes of Health Stroke Scale (NIHSS) was used to assess the neurological defect, and the Activities of Daily Living (ADL) was used to assess recovery of abilities of patients after stroke. Meanwhile, the levels of serum 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) were measured before and after treatment. The dose of venlafaxine used and adverse events were also recorded. RESULTS: Each group had 40 PSD patients. After treatment, the depressive symptoms, neurological defect and living function were significantly improved in both groups. But the patients receiving ginkgo biloba extract plus venlafaxine had the significantly lower average HDRS score (p=0.0008), SDS score (p<0.00001), NIHSS score (p=0.00001), and higher average ADL score (p=0.0005). Meanwhile, compared to the control group, patients in the experiment group had the significantly higher 5-HT (p<0.00001) level and BDNF level (p<0.00001), needed lower dose of venlafaxine (p=0.007), and experienced fewer adverse events. CONCLUSION: These results demonstrated that the ginkgo biloba extract was a good augmentation of venlafaxine in treating PSD and should be further investigated.

Urinary biomarkers for diagnosing poststroke depression in patients with type 2 diabetes mellitus.

BACKGROUND: Depression can seriously affect the quality of life of type 2 diabetes mellitus (T2DM) patients after stroke. However, there were still no objective methods to diagnose T2DM patients with poststroke depression (PSD). Therefore, we conducted this study to deal with this problem. METHODS: Gas chromatography-mass spectroscopy (GC-MS)-based metabolomics profiling method was used to profile the urinary metabolites from 83 nondepressed T2DM patients after stroke and 101 T2DM patients with PSD. The orthogonal partial least-squares discriminant analysis was conducted to explore the metabolic differences in T2DM patients with PSD. The logistic regression analysis was performed to identify the optimal and simplified biomarker panel for diagnosing T2DM patients with PSD. The receiver operating characteristic curve analysis was used to assess the diagnostic performance of this biomarker panel. RESULTS: In total, 23 differential metabolites (7 decreased and 16 increased in T2DM patients with PSD) were found. A panel consisting of pseudouridine, malic acid, hypoxanthine, 3,4-dihydroxybutyric acid, fructose and inositol was identified. This panel could effectively separate T2DM patients with PSD from nondepressed T2DM patients after stroke. The area under the curve was 0.965 in the training set and 0.909 in the validation set. Meanwhile, we found that the galactose metabolism was significantly affected in T2DM patients with PSD. CONCLUSION: Our results could be helpful for future development of an objective method to diagnose T2DM patients with PSD and provide novel ideas to study the pathogenesis of depression.

Inhibitory effects of vitamin E on osteocyte apoptosis and DNA oxidative damage in bone marrow hemopoietic cells at early stage of steroid-induced femoral head necrosis.

Apoptosis and DNA oxidative damage serve significant roles in the pathogenesis of steroid­induced femoral head necrosis. Vitamin E demonstrates anti­apoptotic and anti­oxidant properties. Therefore, the present study investigated the effects of vitamin E on osteocyte apoptosis and DNA oxidative damage in bone marrow hemopoietic cells at an early stage of steroid­induced femoral head osteonecrosis. Japanese white rabbits were randomly divided into three groups (steroid, vitamin E­treated, and control groups), each comprising 12 rabbits. Those in the steroid group (group S) were initially injected twice with an intravenous dose of 100 µg/kg Escherichia coli endotoxin, with a 24 h interval between the two injections, and then with an intramuscular dose of 20 mg/kg methylprednisolone, three times at intervals of 24 h in order to establish a rabbit model of osteonecrosis. The vitamin E treated group (group E) received the same treatment as group S, and were administered 0.6 g/kg/d vitamin E daily from the beginning of modeling. The control group (group C) was injected with normal saline at the equivalent dosage and times as the aforementioned two groups. Two time points, weeks 4 and 6 following the completion of modeling, were selected. Osteonecrosis was verified by histopathology with hematoxylin-eosin staining. The apoptosis rate of osteonecrosis was analyzed by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The apoptosis expression levels of caspase­3 and B­cell lymphoma 2 (Bcl­2), and DNA oxidative damage of bone marrow hematopoietic cells were analyzed by immunohistochemistry. At weeks 4 and 6 following the completion of modeling, the vacant bone lacunae rates of group E were 15.87±1.97 and 25.09±2.67%, respectively, lower than the results of 20.02±2.21 and 27.79±1.39% for group S; and the osteocyte apoptosis indexes of group E were 20.99±2.95 and 33.93±1.62%, respectively, lower than the results of 26.46±3.37 and 39.90±3.74% from group S. In addition, the Bcl-2 expression at week 4 in the femoral head tissues of group E was higher compared with group S; and the proportion of Bcl­2­positive cells of group E was 9.81±1.01%, higher compared with group S at 8.26±1.13%. The caspase­3 staining data at week 4 in femoral head tissues demonstrated that in the 12 femoral heads of group S, four were negative (32%) and eight were positive (68%); in group E, five were negative (45%) and seven were positive (55%); and in group C, 11 were negative (95%) and one was positive (5%). In addition, the DNA oxidative damage rate at week 4 in the bone marrow hemopoietic cells of group E was (7.24±1.44%), lower compared with group S (11.80±1.26%), and higher compared with group C (5.75±1.47%). Vitamin E is effective in intervening in apoptosis through decreasing caspase­3 expression and upregulating Bcl­2 expression, and by alleviating DNA oxidative damage in bone marrow hemopoietic cells at the early stage of steroid­induced femoral head necrosis in rabbit models.

An improved on-line solid phase extraction coupled HPLC-MS/MS system for quantification of sifuvirtide in human plasma.

An improved liquid chromatographic method with on-line solid phase extraction (SPE) and tandem mass spectrometric detection was optimised for quantification of the anti-HIV peptide Sifuvirtide in human plasma. The SPE sorbents, loading buffer composition and other aspects of the on-line SPE column were investigated in detail for efficiently extracting the interesting peptides and simultaneously discarding the large amount of proteins. The gradient elution program was optimised on the analysis column to decrease the matrix effect and obtain excellent selectivity. The multiple charge ion at m/z 946.4 of Sifuvirtide was quantified by a linear ion trap mass spectrometer, operating in the positive mode, and selective reaction monitoring (SRM) acquisition. Method validation results demonstrated that the linear calibration curve covered a range of 6.1-6250 ng/mL, and the correlation coefficients (r(2)) were above 0.992. The lower limit of detection (LLOD) with a signal-to-noise (S/N) ratio higher than 10 was 6.1 ng/mL. The accuracy ranged from -7.6 to 10.6%, and the intra- and inter-batch precisions were less than 8.7% and 5.5%, respectively. Finally, more than nine hundred of samples from a clinical trial was completely analyzed using this on-line SPE coupled HPLC-MS/MS system in one single week, due to the rapid run-time of individual sample (6.5 min).

Differential response of root morphology to potassium deficient stress among rice genotypes varying in potassium efficiency.

Disparity in the root morphology of six rice (Oryza sativa L.) genotypes varying in potassium (K) efficiency was studied with three K levels: 5 mg/L (low), 10 mg/L (moderate) and 40 mg/L (adequate) in hydroponic culture. Morphological parameters included root length, surface area, volume and count of lateral roots, as well as fine (diameter<0.2 mm) and thick (diameter>0.2 mm) roots. The results indicate that the root growth of all genotypes was reduced under low K, but moderate K deficiency increased the root length of the efficient genotypes. At deficient and moderate K levels, all the efficient rice genotypes developed more fine roots (diameter<0.2 mm) than the inefficient ones. Both fine root count and root surface area were found to be the best parameters to portray K stress in rice. In accordance with the root morphology, higher K concentrations were noted in shoots of the efficient genotypes when grown at moderate and deficient K levels, indicating that root morphology parameters are involved in root uptake for K and in the translocation of K up to shoots. K deficiency affected not only the root morphology, but also the root ultra-structure. The roots of high-efficient genotypes had stronger tolerance to K deficient stress for root membrane damage, and could maintain the developed root architecture to adapt to the low K growth medium.