Development of a two-stage biotransformation system for mercury-contaminated soil remediation.

Utilization of bacterial volatilization can be problematic to remediate mercury (Hg)-contaminated soils because most of the Hg in soils is bound to soil particles. The objective of this study was to develop a two-stage system (chemical extraction followed by microbial reduction) for Hg-contaminated soil remediation. The tasks were to (1) select the extraction reagents for Hg extraction, (2) assess the effects of extraction reagents on the growth of Hg-reducing bacterial strains, and (3) evaluate the effectiveness of Ca2+ and Mg2+ addition on merA gene (Hg reductase) induction. Bacterial inhibition was observed with the addition of 0.1 M ethylenediaminetetraacetic acid or citric acid. Up to 65% of Hg was biotransformed (Hg concentration = 69 mg/kg) from the soils after a 24 h extraction using 0.5 M ammonium thiosulfate. Ca2+ and Mg2+ were selected because they have the same electric charge as Hg and the studied groundwater contained high concentrations of Ca2+ and Mg2+. Results showed that the addition of 200 mg/L Ca2+ or 650 mg/L Mg2+ could reach effective merA induction. In the two-stage experiment, 120 mg/kg Hg-contaminated soils were extracted with 2 rounds of extraction processes for 10 h using 0.5 M ammonium thiosulfate. Approximately 77% of Hg was extracted from the soils after the first-step extraction process. Up to 81% of Hg2+ was transformed from the washing solution via the biotransformation processes with Enterobacter cloacae addition and Ca2+ and Mg2+ supplementation. The two-stage remedial system has the potential to be developed into a practical technology to remediate Hg-contaminated sites.

[Premature outflow tract ventricular contraction combined with complete bundle branch block: the characteristic electrocardiographic and ablation target potential features].

Objective: To explore the characteristics of electrocardiogram(ECG) and target potential features of premature ventricular contraction (PVC) in patients with complete left/right bundle branch block (CL/RBBB) and compare with those without CL/RBBB. Methods: A retrospective analysis was done in 8 outflow tract PVC patients with CL/RBBB, who successfully underwent radiofrequency ablation from August 2009 to June 2017. According to the bundle branch block chamber, patients were divided into the complete right bundle branch block (CRBBB) group (n=4) and the complete left bundle branch block (CLBBB) group (n=4). The control group were those who successfully underwent ablation at the same position as the above two groups but without CL/RBBB. The characteristics of ECG and target potential features were compared among groups. Results: One case in the CRBBB group was successfully ablated in the great cardiac vein with precordial R/S>1 transition at V(1) and one case in the CLBBB group was successfully ablated in the right coronary cusp with precordial R/S>1 transition at V(2), while other 6 cases were all with precordial R/S>1 transition at lead V(4). Precordial R/S>1 transition was not later than sinus rhythm (SR) in the CLBBB group. No statistical difference was found in the QRS complex duration between SR and PVC in the CL/RBBB patients [(134.38±23.80)ms vs (156.75±25.93)ms, P>0.05], while statistical difference was shown in the control group [(92.63±5.76)ms vs (140.25±15.97)ms, P<0.05]. Conclusion: Bundle branch block can lead to misjudgment of PVC origin with CL/RBBB during sinus rhythm, thus the origin chamber of the PVC should be determined according to the mapping and ablation result.

[Efficacy and safety of Rivaroxaban anticoagulant therapy in the treatment of atrial fibrillation cryoablation].

Objective: To observe the efficacy and safety of the novel oral anticoagulant Rivaroxaban for anticoagulation therapy in patients with nonvalvular atrial fibrillation (AF) during cryoablation. Methods: A total of 137 AF patients from October 2013 to December 2016 underwent cryoablation were divided into two groups according to the application of anticoagulant drugs: Rivaroxaban group (65 cases) and Heparin group (72 cases). Rivaroxaban group: oral administration of Rivaroxaban 20 mg, once a day, was started 3 days before the cryoablation, no anticoagulant was additionally added during cryoablation, the activated clotting time (ACT) was measured, and oral administration of Rivaroxaban was continued for 3 months after cryoablation. Heparin group: oral administration of Rivaroxaban 20 mg, once a day, was stopped 24 hours before the cryoablation, heparin (100 U/kg) anticoagulation was given during cryoablation, ACT was controlled between 250 and 300 seconds, and oral administration of Rivaroxaban was continued for 3 months after cryoablation. The ACT results, the incidence of bleeding and thromboembolic events between the two groups were compared. Results: The ACT result between the two groups were with statistically significance[(110±16) vs (323±61) seconds, P=0.000)]. The bleeding events for Rivaroxaban group were two cases of local hematoma of the femoral vein puncture site, with the incidence rate of 3.1%(2/65); Heparin group were two cases of local hematoma of the femoral vein puncture site, and one case of epistaxis, with the incidence rate of 4.2%(3/72), with no statistical significance(P=0.549) between the two groups. No thromboembolic event occurred in the Rivaroxaban group, one cerebellar thromboembolic event occurred in the Heparin group during anticoagulant bridging phase after cryoablation. Conclusion: Rivaroxaban is safe and effective for anticoagulation therapy in patients with atrial fibrillation cryoablation.

Cytotoxic metabolites from the fungal endophyte Alternaria sp. and their subsequent detection in its host plant Polygonum senegalense.

From the Egyptian medicinal plant Polygonum senegalense the fungal endophyte Alternaria sp. was isolated. Extracts of the fungus grown either in liquid culture or on solid rice media exhibited cytotoxic activity when tested in vitro against L5178Y cells. Chromatographic separation of the extracts yielded 15 natural products, out of which seven were new compounds, with both fungal extracts differing considerably with regard to their secondary metabolites. Compounds 1, 2, 3, 6, and 7 showed cytotoxic activity with EC 50 values ranging from 1.7 to 7.8 microg/mL. When analyzed in vitro for their inhibitory potential against 24 different protein kinases, compounds 1- 3, 5- 8, and 15 inhibited several of these enzymes (IC 50 values 0.22-9.8 microg/mL). Interestingly, compounds 1, 3, and 6 were also identified as constituents of an extract derived from healthy leaves of the host plant P. senegalense, thereby indicating that the production of natural products by the endophyte proceeds also under in situ conditions within the plant host.

Rocaglamides, glycosides, and putrescine bisamides from Aglaia dasyclada.

A phytochemical analysis of the leaves of Aglaia dasyclada collected in Yunnan Province (People's Republic of China) yielded five cyclopentabenzofurans (1-5) of the rocaglamide family that are common secondary metabolites of Aglaia species as well as four biogenetically related compounds of the aglain (7), aglaforbesin (8) and forbaglin (9, 10) types. In addition, the cinnamic acid amide dasyclamide (6), which is a putative biogenetic precursor of these compounds (7-10), was isolated. The structures of the new compounds (6-10) were assigned unambiguously from the combined use of 1D and 2D NMR spectroscopy and mass spectrometry.

Comparison of conventional phototherapy and fiberoptic phototherapy in the very-low-body-weight infants.

Phototherapy is effectively employed for the treatment of neonatal hyperbilirubinemia, but it may influence the physiological hemodynamics of the infants, such as skin blood flow, insensible water loss and the redistribution of cardiac output. This is a retrospective chart review study involved totally 42 very low birth weight prematures(birth body weight less than 1500 gm, VLBW) who received conventional or fiberoptic phototherapy. Infants with congenital malformation, severe cardiorespiratory instability and the requirement of diuretics, inotropics or blood transfusion were excluded. The body weight loss, daily intake/output and bilirubin level during the initial four days of phototherapy were analyzed. The results showed the efficacy of both methods was the same, while the fiberoptic therapy group had significantly more urine output(p < 0.05), the body weight loss was not statistically significant. It is possible that the fiberoptic therapy group had less insensible water loss and less attenuation of the decrease of renal blood flow, this resulted in more urine output.

Effects of zinc supplementation on the plasma glucose level and insulin activity in genetically obese (ob/ob) mice.

The effects of zinc supplementation (20 mM ZnCl2 from the drinking water for eight weeks) on plasma glucose and insulin levels, as well as its in vitro effect on lipogenesis and lipolysis in adipocytes were studied in genetically obese (ob/ob) mice and their lean controls (+/?). Zinc supplementation reduced the fasting plasma glucose levels in both obese and lean mice by 21 and 25%, respectively (p < 0.05). Fasting plasma insulin levels were significantly decreased by 42% in obese mice after zinc treatment. In obese mice, zinc supplementation also attenuated the glycemic response by 34% after the glucose load. The insulin-like effect of zinc on lipogenesis in adipocytes was significantly increased by 80% in lean mice. However, the increment of 74% on lipogenesis in obese mice was observed only when the zinc plus insulin treatment was given. This study reveals that zinc supplementation alleviated the hyperglycemia of ob/ob mice, which may be related to its effect on the enhancement of insulin activity.

Zinc supplementation on serum levels and hepatic conversion of thyroid hormones in obese (ob/ob) mice.

The supplemental effects of zinc on thyroid status in obese (ob/ob) mice were studied. Four-week-old obese mice and their lean controls were fed either a basal diet or a zinc-supplemented diet (200 mg/kg diet) for 8 wk. Following the 8-wk basal diet, obese mice had lower serum T4 values, as well as hepatic T4 and T3 values, than lean mice (p < 0.05). A significant decrease in hepatic 5'-deiodinase activity was also observed in obese mice. Dietary zinc supplementation significantly reduced serum T4 levels in both the obese and lean mice. However, the zinc-supplemented effects on diminishing hepatic T4 and T3 values, as well as on 5'-deiodinase activities, were found only in obese mice (p < 0.05). Furthermore, the 5'-deiodinase activities in hepatic microsomal pellets after incubation with various zinc concentrations (0.5, 1.0, and 2.5 mM) were also examined. The 5'-deiodinase activities, in hepatic samples from all mice, were significantly attenuated by zinc treatments. However, this effect was more predominant in obese mice following the addition of 0.5 mM zinc. This study suggests that a lower hepatic 5'-deiodinase activity, resulting from a higher zinc level, might be related to abnormal energy metabolism in the ob/ob mice.

Zinc supplementation aggravates body fat accumulation in genetically obese mice and dietary-obese mice.

A perturbation of zinc metabolism has been noted in numerous laboratory animals with diabetes and obesity. The effects of zinc supplementation on body fat deposition in two types of experimental obese mice: genetically obese (ob/ob) mice and high-fat diet-induced ICR obese (HF) mice were investigated in this study. Their lean controls were +/? mice, and ICR on basal diet, respectively. The mice in the zinc-supplemented groups were administered 200 mg/kg zinc in their diets for 6 wk. Both the ob/ob mice and the HF mice, that were fed a diet containing a marginal zinc dosage (4-6 mg/kg), had lower zinc levels in their serum and carcass, and higher body fat content than their respective lean controls (p < 0.01). After zinc supplementation, ob/ob mice and the HF mice significantly (p < 0.05) increased their body fat by 49.4% and 18.9%, respectively. This study revealed that body fat deposition can be aggravated by zinc supplementation in both types of obese mice. Zinc may be associated with the energy homeostasis of obesity, via its interaction with dietary fat consumption.

Dietary copper supplementation increases the catecholamine levels in genetically obese (ob/ob) mice.

The interactive relationship between Cu deficiency and depressed synthesis of certain neurotransmitters has been recognized. To investigate the effects of dietary Cu supplementation on the catecholamine levels in genetically obese mice, male obese (ob/ob) mice and their lean (+/?) counterparts were administered either a control diet (4.0 mg/kg) or a Cu-supplemented diet (50 mg/kg) for 4 wk. The ob/ob mice that were fed a control diet showed lower liver and higher plasma levels of Cu. Depressed levels of plasma and brain catecholamines were also found in ob/ob mice that were fed the control diet. The ob/ob mice that received a Cu-supplemented diet showed significant increases in the levels of catecholamine in the plasma and brain. This study showed that catecholamine levels in ob/ob mice can be increased by dietary Cu supplementation. However, the interaction between Cu and sympathetic nervous activity in obesity was not elucidated in this study.

Expression of a Drosophila GATA transcription factor in multiple tissues in the developing embryos. Identification of homozygous lethal mutants with P-element insertion at the promoter region.

GATA transcription factors are DNA-binding proteins that recognize the core consensus sequence, WGATAR. Previous studies indicated that GATA factors play ann important role in the development of tissue-specific functions in vertebrates. Here we report the identification of a new Drosophila melanogaster GATA factor, dGATAc, which displays a distinct expression pattern in embryos. The local concentration of dGATAc transcripts varies at different stages, being most prominent in the procephalic region at stages 6-10 and in the posterior spiracles, the gut, and the central nervous system at stages 11-13. On the basis of its predicted sequence, DNA-binding assays were performed to confirm that the dGATAc gene encodes a zinc finger protein that can bind the GATA consensus motif with predicted specificity. Two independent mutants carrying a P-element insertion at the dGATAc gene promoter region were identified that are homozygous lethal at the embryonic stage. Using a genetic scheme, it was demonstrated that the lack of dGATAc function can block normal embryonic development. Our results suggest that the dGATAc protein is a tissue-specific transcription factor that is vital to the development of multiple organ systems in D. melanogaster.

[Studies on the chemical constituents of Fritillaria taipaiensis L].

A new C-nor-D-homo-steroidal alkaloid named taipaienine, together with five known alkaloids namely chuanbeinone, imperialine, verticinone, perimissine and isoverticine were isolated from the bulbs of Fritillaria taipaiensis L. var. ningxiaensis Y. et W.. The unusual structure of taipaienine was a first sample with a hydroxyl group substituted at C-25 of (22)R-trans quinolizidine moiety with orientation of nitrogen lone pair. Their structures were determined by various spectral analyses.

[Studies on the chemical constituents of Croomia japonica Miq].

A new steroid alkaloid, namely croomionidine (II), together with four known compounds pachysamine A(I), croomine (III), didehydrocroomine (IV) and beta-sitosterol were isolated from the roots of Croomia japonica Miq. Their structures were identified by IR, MS, 1H NMR, 13C NMR and chemical conversion.

Studies on bioactive components from Chinese medicinal plants.

Several novel bioactive components isolated from Chinese medicinal plants will be presented. These include novel maytansinoid tumor inhibitors, some new ent-kaurane and rosane diterpenoids from Mallotus anomalus Meer et Chun (Euphorbiaceae), as well as novel insecticide, stemona alkaloids from Stemona parviflora C. H. Wright (Stemonaceae). Both are native plants of Hainan island, China. 2D NMR techniques such as mono and hetero-COSY, NOESY, COLOC as well as 1H-NMR line broadening effect were utilized for structure elucidation. The separation techniques, structure elucidations and bioassay results will be reported.

[Studies on the chemical constituents of Melia azedarach L].

Melianoninol (I), melianol (II), melianone (III), meliandiol (IV), vanillin (V) and vanillic acid (VI) were isolated from the fruits of Melia azedarach L.. The structure of melianoninol, a new compound, was elucidated by IR, MS, 1H NMR, 13CNMR and other spectral evidences. The new compound possesses some anti-feeding properties against the imported cabbage worm (Pieris rarae L.).