[Toxic effects of sublethal acetochlor with sublethal doses on earthworms in soil using multi-endpoints system]. / äºšè‡´æ­»å‰‚é‡ä¹™è‰èƒºå¯¹èš¯èš“çš„æ¯’æ€§æ•ˆåº”åŠæ•æ„Ÿç”Ÿç‰©æ ‡è®°ç‰©.

In this study, we examined the toxic effect of sublethal doses of acetochlor (1, 2, 4, 8 mg·kg-1) on earthworms by exogenous addition. The growth inhibition rate, cytochrome P450 isozymes (CYP1A2, 2C9 and 3A4) activities and the metabolomics were analyzed after seven days of exposure, to infer the toxicity threshold of acetochlor, screen the sensitive biomarkers from the levels of the individual, detoxified enzymes and small molecular metabolites, and elucidate the underlying toxicity mechanism. The results showed that CYP1A2, 2C9 and 3A4 activities were all significantly inhibited, and that the levels of ten metabolites (fructose-6-diphosphate, cytosine monophosphate, uridine monophosphate, adenosine monophosphate, adenosine, xanthine, fumaric acid, dihydroxyglutaric acid, ornithine and 16-hydroxyeicosatetraenoic acid) were significantly decreased by acetochlor exposure. The levels of six metabolites (adenosine succinic acid, succinic acid, arginine, tryptophan, asparagine and phenylalanine) were significantly increased when earthworms being exposed to 2-8 mg·kg-1 acetochlor. Acetochlor exposure caused oxidative damage to earthworms, weakened the glycolysis, disturbed the tricarboxylic acid cycle, disordered the purine and pyrimidine metabolism, and impaired the amino acids metabolism. Compared with the end point at individual level, the above 16 small molecule metabolites and CYP isozymes activities were more sensitive to acetochlor exposure. It was thus recommended that CYP isozymes (1A2, 2C9, and 3A4) activities and small molecular metabolites could be used as a set of biomarkers to diagnose the acetochlor pollution, given their high sensitivity and accuracy.

Effect of Intensive Periodontal Therapy on Blood Pressure and Endothelial Microparticles in Patients With Prehypertension and Periodontitis: A Randomized Controlled Trial.

BACKGROUND: Although some studies show a positive association between periodontitis and blood pressure (BP) elevation, research on the effect of intensive periodontal treatment on decline in BP levels and endothelial microparticles (EMPs) without any antihypertensive management is lacking. Therefore, the present clinical trial explores whether intensive periodontal therapy would lower BP levels and EMPs of patients with prehypertension with periodontitis. METHODS: From a total 107 patients, 95 underwent randomization (47 assigned to control-treatment [CT] group and 48 assigned to intensive-treatment [IT] group) and completed the trial. Patients received intervention for 4 consecutive weeks and were followed for 6 months. Levels of BP and EMPs were evaluated at baseline and 1, 3, and 6 months after intervention. RESULTS: Periodontal conditions were significantly improved (P <0.05) 6 months after intensive periodontal treatment. In parallel, the primary outcomes including systolic and diastolic BP and EMPs were markedly reduced in the IT group compared with the CT group (absolute difference: 12.57 and 9.65 mm Hg and 581.59/µL, respectively; 95% confidence intervals: 10.45 to 14.69, 7.06 to 12.24, and 348.12 to 815.06, respectively; P <0.05). Reduction in BP levels and EMPs was related to improvement in probing depth (r = 0.358, 0.363, and 0.676, respectively, by the Pearson product-moment correlation; P = 0.009, 0.008, and P <0.001, respectively). CONCLUSION: To the best knowledge of the authors, the present study demonstrates for the first time that intensive periodontal intervention without any antihypertensive medication therapy may be an effective means to lower levels of BP and EMPs in patients with prehypertension with periodontitis.

The antitumor effects of selenium compound Na5SeV5O18.3H20 in K562 cell.

With an approach to study the anti-tumor effects and mechanism of selenium compound, we investigated the anti-tumor activity and mechanism of Na5SeV5O18.H20 (NaSeVO) in K562 cells. The results showed that 0.625-20 mg/L NaSeVO could significantly inhibit the proliferation of K562 cells in vitro in a time- and concentration-dependent manner as determined by microculture tetrazolium (MTT) assay, the IC50 values were 14.41 (4.45-46.60) and 3.45 (2.29-5.22) mg/L after 48 h and 72 h treatment with NaSeVO respectively. In vivo experiments demonstrated that i.p. administration of 5, 10 mg/kg NaSeVO exhibited an significant inhibitory effect on the growth of transplantation tumor sarcoma 180 (S180) and hepatoma 22 (H22) in mice, with inhibition rate 26.8% and 58.4% on S180 and 31.3% and 47.4% on H22, respectively. Cell cycle studies indicated that the proportion of G0/G1 phase was increased at 2.5 mg/ L while decreased at 10 mg/L after treatment for 24, 48 h. Whereas S phase was decreased at 2.5-5 mg/L and markedly increased at 10 mg/L after treatment for 48 h. After treatment for 24 h, 10 mg/L NaSeVO also markedly increased S and G2/M phases. Take together, the result clearly showed that NaSeVO markedly increased S and G2/M phases at 10 mg/L. The study of immunocytochemistry showed that the expression bcl-2 is significantly inhibited by 10 mg/L NaSeVO, and bax increased. Morphology observation also revealed typical apoptotic features. NaSeVO also significantly caused the accumulation of Ca2+ and Mg2+, reactive oxygen species (ROS) and the reduction of pH value and mitochondrial membrane potential in K562 cells as compared with control by confocal laser scanning microscope. These results suggest that NaSeVO has anti-tumor effects and its mechanism is attributed partially to apoptosis induced by the elevation of intracellular Ca2+, Mg2+ and ROS concentration, and a reduction of pH value and mitochondria membrane potential (MMP).

Effects of simvastatin gel on bone regeneration in alveolar defects in miniature pigs.

BACKGROUND: Currently, the most commonly used treatment methods for repairing alveolar furcation defects are periodontal guided tissue regeneration (GTR) and bone grafting. The objective of this study was to investigate the effects of simvastatin/methylcellulose gel on bone regeneration in alveolar defects in miniature pigs. METHODS: Alveolar defects were produced in 32 teeth (the third and fourth premolars) of 4 miniature pigs. The 32 experimental teeth were divided into 5 groups comprising control (C) and treatment (T) teeth: (1) empty defects without gel (group C0, n = 4); (2) defects injected with methylcellulose gel (group C1, n = 4); (3) defects injected with 0.5 mg/50 µl simvastatin/methylcellulose gel (group T1, n = 8); (4) defects injected with 1.5 mg/50 µl simvastatin/methylcellulose gel (group T2, n = 8); and (5) defects injected with 2.2 mg/50 µl simvastatin/methylcellulose gel (group T3, n = 8). Every week after surgery, the furcation sites were injected once with gel. At the eighth week after surgery, the 4 pigs were sacrificed and underwent macroscopic observation, descriptive histologic examination, and regenerate bone quantitative histologic examination. RESULTS: At 8 weeks after surgery, the defect sites in the treatment groups were completely filled in with new bone and fibrous tissue. There was little new bone in the C0 and C1 groups, and only a small number of osteoblasts and proliferative vessels could be seen on microscopic examination. CONCLUSIONS: Miniature pigs are an ideal experimental animal for establishing a model of alveolar defects using a surgical method. Local application of simvastatin/methylcellulose gel can stimulate the regeneration of alveolar bone in furcation defect sites, because it promotes the proliferation of osteoblasts. The best dose of simvastatin gel to stimulate bone regeneration is 0.5 mg.

[Prevalence and influencing factors of dental erosion among college students].

OBJECTIVE: To investigate the prevalence and influencing factors of dental erosion among college students in Guangzhou and to provide necessary information for the prevention. METHODS: A total of 1704 16-24-year-old students from six colleges or universities were assessed for dental erosion. Data on the social economical status, eating habits, oral hygiene habits, and other related factors were obtained through questionnaire. The influencing factors were analyzed by chi(2)-test and logistic regression analysis. RESULTS: Five hundreds and one of the 1704 subjects suffered from dental erosion (29.4%). The teeth most frequently affected were the upper and lower incisors and first mandibular molar. For tooth surfaces were incisal/occlusal surfaces [66.1% (5491/8311)] and labial/buccal surfaces [31.0% (2574/8311)]. Logistic regression analysis showed that female, those who were not the only child in the family, and students who consumed carbonated drinks more than once per week or drank 500 ml or more of acidic beverages per week were more likely to have dental erosion. CONCLUSIONS: Control of the consuming of acidic beverages is an important measure for the prevention of dental erosion.

[A study on oral health behavior and other related factors between children with high dmft and no caries].

OBJECTIVE: To explore the risk factors of children with high dmft. METHODS: In suburban of Guangzhou, oral health of 401 3 - 4-year-old children were examined and structured questionnaire were completed by their parents. 120 children with highest number of dmft (dmft > or = 5) and 118 caries-free children were chosen for case-control analysis. RESULTS: The results of logistic regression analysis showed that the factors associated with high dmft were developmental defect of enamel, visible plaque index, frequency of toothbrushing, frequency of sugar consumption, and income. CONCLUSIONS: Advocating brushing teeth at least twice daily, controlling the frequency of sugar consuming, reducing the developmental defect of enamel and paying more attention to the oral health of lower income population may effectively reduce dental caries of the children.