Biomedical and environmental sciences : BES最新文献

Objective: To study the modulatory effect of distillate of Ocimum sanctum (traditionally known as Tulsi) leaf extract (DTLE) on genotoxicants.

Methods: In the present investigation, we studied the antigenotoxic and anticlastogenic effect of distillate of Tulsi leaf extract on (i) human polymorphonuclear leukocytes by evaluating the DNA strand break without metabolic activation against mitomycin C (MMC) and hexavalent chromium (Cr+6) and (ii) human peripheral lymphocytes (in vitro) with or without metabolic activation against mitomycin C (MMC), hexavalent chromium (Cr+6) and B[a]P by evaluating chromosomal aberration (CA) and micronucleus assay (MN). Three different doses of DTLE, 50 microL/mL, 100 microL/mL, and 200 microL/mL were selected on the basis of cytotoxicity assay and used for studying DNA strand break, chromosomal aberration and micronucleus emergence. The following positive controls were used for inducing genotoxicity and clastogenicity: MMC (0.29 micromol/L) for DNA strand break, chromosomal aberration and 0.51 micromol/L for micronucleus assay; Potassium dichromate (Cr+6) 600 micromol/L for DNA strand break and 5 micromol/L for chromosomal aberration and micronucleus assay; Benzo[a]pyrene (30 micromol/L) for chromosomal aberration and 40 micromol/L for micronucleus assay. The active ingredients present in the distillate of Tulsi leaf extract were identified by HPLC and LC-MS.

Results: Mitomycin C (MMC) and hexavalent chromium (Cr+6) induced statistically significant DNA strand break of respectively 69% and 71% (P<0.001) as revealed by fluorometric analysis of DNA unwinding. Furthermore, the damage could be protected with DTLE (50 microL/mL, 100 microL/mL, and 200 microL/mL) on simultaneous treatment. Chromosomal aberration and micronucleus formation induced by MMC, Cr+6 and B[a]P were significantly protected (P<0.001) by DTLE with and without metabolic activation.

Conclusion: Distillate of Tulsi leaf extract possesses antioxidants contributed mainly by eugenol, luteolin and apigenin as identified by LC-MS. These active ingredients may have the protective effect against genotoxicants.

Objective: To study the metabolism of 14C-deltamethrin in rats.

Methods: Rats were dosed orally and i.p. with a single dose of 14C-deltamethrin (0.64 mg/Kg) body weight. The required dose was applied daily for 3 days. At the end of the experiment, selected organs, such as liver, kidney, fat, intestine, and blood were excised for radioassay of 14C-content.

Results: Deltamethrin was almost eliminated from the body within 1-3 days. The main portion of 14C-residues was extracted from urine (38%, 32%) and feces (20%, 24%) with a little amount remained in various organs.

Conclusion: The elimination and distribution of 14C-radioactivity in rats treated orally and intraperitoneally signify that deltamethrin is bioavailable in urine and feces.

Objective: To determine the metal contents of lichen species from East Black Sea region of Turkey for investigation of trace metal pollution sourced traffic.

Methods: The levels of copper, cadmium, lead, zinc, manganese, iron, chromium, nickel, cobalt, palladium in lichen samples collected from East Black Sea region of Turkey were determined by flame and graphite furnace atomic absorption spectrometry after microwave digestion method. The accuracy of the method was corrected by standard reference material (NIST SRM IAEA-336 Lichen).

Results: The contents of investigated trace metals in lichen samples were 7.19-22.4 microg/g for copper, 0.10-0.64 microg/g for cadmium, 4.03-44.6 microg/g for lead, 14.5-41.8 microg/g for zinc, 25.8-208 microg/g for manganese, 331-436 microg/g for iron, 1.20-3.01 microg/g for chromium, 1.48-3.90 microg/g for nickel, 0.20-3.55 microg/g for cobalt, 0.11-0.64 microg/g for palladium. The results were compared with the literature values.

Conclusion: Some lichen species such as Xanthoparmelia conspersa, Xanthoria calcicola, Peltigera membranacea, and Physcia adscendens are accumulated trace metals at a high ratio.

Objective: To study the possible effect of tetracycline on protease-resistant activity in vitro and infectivity in vivo of a scrapie strain 263K.

Methods: Scrapie pathogens were incubated with tetracycline at different concentrations for various periods of time and protease-resistant PrP signals were evaluated with proteinase K-treatment and Western blots. The preparations treated with tetracycline were intracerebrally inoculated into golden hamsters and typical TSE manifestations were noted. PrPSc in brain tissues of the infected animals was detected by PrP specific Western blot assays.

Results: Protease-resistant PrP was significantly reduced in or removed from the preparations treated with tetracycline in a dose-dependant manner. Compared with the control group after incubated for 53.75 +/- 0.50 days, the preparations treated with 5 mmol/L and 20 mmol/L tetracycline prolonged the incubation time of 61.5 +/- 1.73 and 59.5 +/- 0.58 days (P < 0.05).

Conclusion: Treatment of scrapie pathogen 263K with tetracycline reduces or removes its protease-resistant activity in vitro.

Objective: To study the association of the apolipoprotein B gene polymorphisms with essential hypertension in Northern Chinese Han population.

Methods: XbaI and EcoRI polymorphisms of the apolipoprotein B (APOB) gene were genotyped by polymerase chain reaction (PCR) and restriction fragment-length polymorphism (RFLP) method in 503 unrelated hypertensive patients and 490 healthy controls recruited from international collaborative study of cardiovascular disease in Asia (InterAsia).

Results: The difference in the genotypic distributions could be neglected across the groups. The prevalence of X+ allele in healthy controls (4.8%) was less frequent in Chinese, and there was no significant difference in the frequency of the X+ allele between cases (5.7%) and controls (P = 0.38). The observed E- allele frequencies were closely similar among groups (5.9% in cases vs 5.0% in controls, P = 0.39). Logitstic regression analyses revealed that the lack of association still persisted after adjustment of other environmental factors. Haplotype analysis showed that X-E+ was most frequent and no haplotype could significantly contribute to essential hypertension.

Conclusion: The APOB gene XbaI and EcoRI polymorphisms are not associated with essential hypertension in the Northern Chinese Han population. Future studies on single nucleotide polymorphisms in larger samples are needed to further investigate the possible contribution of the APOB gene to essential hypertension.

Objective: To investigate the feasibility of reducing THM precursors and controlling bromate taste and odor in drinking water taken from the Yellow River by an ozonation combined system.

Methods: The appropriate ozone dosage was determined, and then the changes of TOC, UV254 and THM formation potential (THMFP) in the combined system were evaluated.

Results: One mg/L ozone could effectively remove taste and odor and meet the maximum allowable bromate level in drinking water. The pre-ozonation increased THMFP, but the conventional treatment system could effectively reduce the odor. The bio-ceramic filter could partly reduce CHCl3FP, but sometimes might increase CHCl2BrFP and CHClBr2FP. The biological activated carbon (BAC) filter could effectively reduce CHCl3FP and CHCl2BrFP, but increase CHClBr2FP. Compared with other filters, the fresh activated carbon (FAC) filter performed better in reducing THMFP and even reduced CHClBr2FP.

Conclusion: The combined system can effectively reduce taste, odor, CHCl3FP, and CHCl2BrFP and also bring bromate under control.

Objective: To establish a conceptual model of automatic early warning of infectious diseases based on internet reporting surveillance system, with a view to realizing an automated warning system on a daily basis and timely identifying potential outbreaks of infectious diseases.

Methods: The statistic conceptual model was established using historic surveillance data with movable percentile method.

Results: Based on the infectious disease surveillance information platform, the conceptual model for early warning was established. The parameter, threshold, and revised sensitivity and specificity of early warning value were changed to realize dynamic alert of infectious diseases on a daily basis.

Conclusion: The instructive conceptual model of dynamic alert can be used as a validating tool in institutions of infectious disease surveillance in different districts.

Objective: To investigate the application of BPDE-albumin adducts as monitoring biomarkers for coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs) and to explore possible relationship between BPDE-albumin adducts and urinary 1-hydroxypyrene (1-OHP) levels in them.

Methods: Thirty-seven coke oven workers from a coke plant and 47 controls without the occupational exposure to PAHs were recruited in this study. The levels of plasma BPDE-albumin adducts and urinary 1-OHP were analyzed using high performance liquid chromatography.

Results: The median levels of BPDE-albumin adducts (42.10 fmol/mg albumin) and urinary 1-OHP (5.46 micromol/mol creatinine) were significantly higher in coke oven workers than in controls (14.16 fmol/mg albumin, 2.96 micromol/mol creatinine, respectively; P<0.01). Multiple logistic regression analysis showed that coke oven workers were at higher risk of having BPDE-albumin adduct levels above 25.30 micromol/mg albumin (OR=1.79, P<0.01) and urinary 1-OHP levels above 4.13 micromol/mol creatinine (OR=2.45, P<0.05). There was a positive correlation between the levels of BPDE-albumin adducts and urinary 1-OHP in all subjects (rs=0.349, P<0.01).

Conclusion: BPDE-albumin adduct is a useful biomarker for monitoring long-term exposure to PAHs, and plasma BPDE-albumin adducts level is significantly correlated to urinary 1-OHP levels in coke oven workers.

Objective: To investigate the effect of lidamycin (LDM) on telomerase activity in human hepatoma BEL-7402 cells under the condition of LDM inducing mitotic cell death and senescence.

Methods: Chromatin condensation was detected by co-staining with Hoechst 33342 and PI. Cell multinucleation was observed by Giemsa staining and genomic DNA was separated by agarose gel electrophoresis. Fluorescent intensity of Rho123 was determined for mitochondrial membrane potential. MTT assay and SA-beta-gal staining were employed to analyze the senescence-like phenotype. The expression of proteins was analyzed by Western blot. Telomerase activity was assayed by telomerase PCR-ELISA.

Results: Mitotic cell death occurred in LDM-treated cells characterized by unique and atypical chromatin condensation, multinucleation and increased mitochondrial membrane potential. However, no apoptotic bodies or DNA ladders were found. In addition, apoptosis-related proteins remained nearly unaltered. Senescence-like phenotype was identified by increased and elongated size of cells, growth retardation, enhanced SA-beta-gal activity and the changes of senescence-related protein expression. Telomerase activity markedly decreased (P<0.01) in LDM-treated hepatoma BEL-7402 cells.

Conclusion: Mitotic cell death and senescence could be triggered simultaneously or sequentially after exposure of hepatoma BEL-7402 cells to LDM. The decrease in telomerase activity may play a key role in the defective mitosis and aging morphology. Further investigation of detailed mechanism is needed.

Objective: To evaluate the protective efficacy of gossypin (3,3',4',5,7,8-hexahydroxyflavone 8-glucoside) by administering it intraperitoneally, for dose, time, and vehicle dependent effects against sulphur mustard (SM), administered through percutaneous route in mice.

Methods: SM (diluted in PEG-300) was administered percutaneously. The protective efficacy of gossypin was evaluated by administering it intraperitoneally (50, 100, 200, and 400 mg/kg), in various vehicles (water, PEG-300 and DMSO), and time intervals (30 min prior, simultaneous and 2 h post). The time dependent protection of gossypin (200 mg/kg in PEG-300; i.p.) was also evaluated using selected biochemical variables (GSH, GSSG, MDA, total antioxidant status, Hb, WBC count, RBC count, glutathione peroxidase, glutathione reductase, and superoxide dismutase) and liver histology. The protection of gossypin by oral route was also evaluated against percutaneously administered SM.

Results: The protection against systemic toxicity of SM (LD50 8.1 mg/kg) was better when gossypin was given with PEG-300 (8.0 folds) than DMSO (5.7 folds). No protection was observed when gossypin was administered with water. Good protection (8.0 folds) was observed when gossypin was administered (200 mg/kg in PEG-300; i.p.) at 30 min prior or simultaneous to SM exposure, but no protection was observed when gossypin was administered 2 h post to SM exposure. A significant weight loss was observed 7 days after SM administration (2 LD50), with a significant increase in RBC and Hb. A significant decrease in total antioxidant status of plasma, liver GSH and GSSG levels, and in the activities of glutathione peroxidase, glutathione reductase and superoxide dismutase was also observed 7 days after SM administration. SM treated mouse liver also showed necrosis. A significant protection was observed when gossypin (200 mg/kg in PEG-300; i.p.) was administered either as a pretreatment (30 min before) or simultaneous treatment, and not as a post treatment (2 h). The protective efficacy of gossypin was better through oral route when administered with DMSO (4.8 folds) than with PEG-300 (2.4 folds). No protection was observed when gossypin was administered orally with water.

Conclusion: Percutaneous administration of SM induces oxidative stress and gossypin can protect it as a prophylactic agent by intraperitoneal or oral routes.