[Quantitative risk assessment of occupational exposure to PCDD/Fs in the waste incineration industry].

Objective: To analyze the level of PCDD/Fs exposure of occupational workers in the waste incineration industry and explore the risk of occupational exposure. Methods: In September 2021, literature on environmental PCDD/Fs exposure in waste incineration plants published from the establishment of the database to February 10, 2021 was retrieved from CNKI database. A total of 1365 literatures were retrieved, and 7 met the criteria for inclusion. The US Environmental Protection Agency (EPA) inhalation risk model was used to assess and analyze carcinogenic and non-carcinogenic risks of PCDD/Fs exposure among occupational workers in the waste incineration industry. Results: A total of 86 sampling sites were included in incineration plants in 7 regions. The study of Wuhan area showed that the concentration of working environment near the waste incinerator in the same factory was the highest, followed by the rest and office area in the factory. The concentration of PCDD/Fs in waste incinerators was the highest in Southwest China (4880.00-24880.00 pg TEQ/m(3)), and the lowest in Shenzhen (0.02-0.44 pg TEQ/m(3)). According to the cancer risk assessment, with the increase of exposure years, the risk of cancer increased. The highest risk of cancer was found in the waste incineration plants in Southwest China. When the exposure period was 1 year, the risk was moderate (22.40×10(-6)-114.20×10(-6)). When the exposure time was more than 5 years, the risk of cancer was high. In Jinan, workers working near the incinerator had a moderate risk of cancer after five years of exposure. In Zhejiang, workers were at medium risk of cancer after exposure for more than 20 years. Workers in Wuhan, Shanghai, Zhejiang Province, Shenzhen and the Pearl River Delta were still at low risk of cancer after 40 years of occupational exposure. HQ>1 of workers working near the waste incinerators in Jinan, Zhejiang Province and Southwest China, and the qualitative evaluation results showed that the non-carcinogenic risk was unacceptable. Conclusion: There are great differences in PCDD/Fs of occupational exposure in waste incineration industry, and the occupational exposure exceeding the occupational exposure limit has higher carcinogenic and non carcinogenic risks.

Effect of fermented Ginkgo biloba leaves on nutrient utilisation, intestinal digestive function and antioxidant capacity in broilers.

1. A total of 648 one-day-old broiler chicks were randomly allocated into six equal groups to investigate the effect of diet supplemented with fermented Ginkgo biloba leaves (FGBL) at different levels on nutrient utilisation, intestinal digestive function and antioxidant activity. 2. Broilers in the six groups were offered basal diet supplemented with either 0, 1.5, 2.5, 3.5, 4.5 and 5.5 g/kg FGBL during the 42-d experiment, respectively. 3. Birds fed with 3.5 g/kg FGBL diet exhibited increased (P < 0.05) body weight gain, feed intake, apparent total tract retention (ATTR) of ether extract (EE) and relative weight of duodenum. Diets supplemented with FGBL increased (P < 0.05) antioxidant and digestive enzyme activities, and decreased malondialdehyde (MDA) concentrations at different degrees in pancreas and small intestine. The expression of antioxidant related genes was up-regulated (P < 0.05) by the transcription factor Nrf2 in small intestine, especially with supplementation of 3.5 and 4.5 g/kg FGBL in the diet. However, 5.5 g/kg diet significantly decreased (P < 0.05) feed conversion ratio and catalase activity (CAT) in the duodenum. 4. Body weight, relative weight of duodenum, amylase and trypsin activities in ileum, total antioxidant capacity (T-AOC) and CAT in duodenum, and glutathione peroxidase (GSH-PX) in ileum increased linearly and quadratically with FGBL content. Activities of amylase in pancreas, trypsin in jejunum, lipase in ileum, and GSH-PX in duodenum and jejunum increased linearly with FGBL content. Body weight gain, ATTR of EE, activities of trypsin in pancreas and amylase in jejunum, total superoxide dismutase activity in duodenum, T-AOC level and concentrations of MDA in the jejunum and ileum showed a quadratic (P < 0.05) dose response as supplemental FGBL level increased. 5. In conclusion, the addition of FGBL had the potential to improve nutrient utilisation, intestinal digestive function and antioxidant activity of broilers. The optimal dietary supplementation dose for broiler production seemed to be 3.5 to 4.5 g/kg.

Effects of c-Jun N-terminal kinase on Activin A/Smads signaling in PC12 cell suffered from oxygen-glucose deprivation.

Activin A (Act A), a member of transforming growth factor-ß (TGF-ß) superfamily, is an early gene in response to cerebral ischemia. Growing evidences confirm the neuroprotective effect of Act A in ischemic injury through Act A/Smads signal activation. In this process, regulation networks are involved in modulating the outcomes of Smads signaling. Among these regulators, crosstalk between c-Jun N-terminal kinase (JNK) and Smads signaling has been found in the TGF-ß induced epithelial-mesenchymal transition. However, in neural ischemia, the speculative regulation between JNK and Act A/Smads signaling pathways has not been clarified. To explore this issue, an Oxygen Glucose Deprivation (OGD) model was introduced to nerve-like PC12 cells. We found that JNK signal activation occurred at the early time of OGD injury (1 h). Act A administration suppressed JNK phosphorylation. In addition, JNK inhibition could elevate the strength of Smads signaling and attenuate neural apoptosis after OGD injury. Our results indicated a negative regulation effect of JNK on Smads signaling in ischemic injury. Taken together, JNK, as a critical site for neural apoptosis and negative regulator for Act A/Smads signaling, was presumed to be a molecular therapeutic target for ischemia.

[The relationships of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) inhalational dose and oxidative damage in foundry workers].

Objective: To investigate the potential dose-response relationship between PCDD/Fs inhalational exposure and oxidative damage to DNA and lipid in foundry workers. Methods: The participants were divided into three groups, including exposure group, administrator group and control group. The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in air environment were determined by isotope dilution high resolution capillary column gas chromatography/high resolution mass spectrometry (HRGC-HRMS). The inhalational dose of PCDD/Fs were evaluated by Houmen's model. Urinary 8-OHdG was analyzed by high performance liquid chromatography-electrochemical detector (HPLC-ECD). Urinary 8-iso-PGF2ɑ were determined by ELISA. Results: The PCDD/Fs environmental concentrations of three groups (pg·TEQ/m) were 0.21±0.08, 0.03±0.01, 0.0012±0.0007 (P<0.05) , respectively. The inhalational dose of exposure group (92.54 (32.90~264.49) fg·TEQ/kg·d) was 5.4 folds higher than the administrator group, and was 201 times more than control group. The levels of urinary 8-OHdG (nmol/L crea) of three groups were 3.25 (1.07~15.36) , 2.72 (0.75~16.07) , 2.17 (0.38~17.07) (P<0.05) and the levels of urinary 8-iso-PGF2ɑ (nmol/L crea) were 19.11 (9.33~76.50) , 20.95 (8.40~79.31) , 11.48 (4.85~37.80) (P<0.05) , respectively. The multiple linear regression analysis revealed that there were significantly increased trend for levels of urinary 8-OHdG and 8-iso-PGF2ɑ as PCDD/Fs exposure levels increased, after adjustment for age, sex, smoking statue, alcohol use and BMI (P<0.01). Conclusion: There was a dose-response relationship between PCDD/Fs inhalational exposure and oxidative damage in foundry workers.

Establishment of a novel human esophageal squamous cell carcinoma cell line (ESC-410) and its partial biological characterization.

Esophageal cancer exhibits an uneven geographical distribution strikingly, resulting in focal endemic high-incidence areas in several countries worldwide including China, which might be associated with the environmental and genetic risk factors in those areas. Permanent cancer cell lines are invaluable tools in understanding the biology of cancers and experimental therapeutics. To enrich cell line panel and animal models of human esophageal squamous cell carcinoma (ESCC) from different geographical areas and investigate the environmental and genetic risk factors in the carcinogenesis of ESCC, a novel human esophageal squamous cancer cell line (ESC-410) was established. The cell line grew adherent as a monolayer and maintained stable growth rate with a doubling time of 53 h and distinct epithelial morphological appearance; it was maintained in vitro for 18 months and subcultured for more than 50 passages. Ultrastructural examination revealed large irregular nuclei, desmosome, and tonofilaments; karyotype analysis showed a modal number of chromosomes that ranged from 35 to 73, with a median of 57, and 77% of analyzed cells were hyperdiploidy; reverse transcription polymerase chain reaction (RT-PCR) detected the mRNA expressions of CK8, CK18, and CK19 in the established cells; immunofluorescence assay identified the protein expressions of neurotrophin receptor p75 and integrin α6 (CD49f) in the ESC-410 cell line; xenotransplantation of ESC-410 cells into athymic nude mice subcutaneously induced the formation of solid tumor masses in about 2 weeks. By histopathological examination, heterogeneity of xenograft tumor was observed, as same as that of human primary ESCC. All findings and evidence in this experimental study suggested that this cell line might be a useful model in vitro and in vivo in cellular and molecular studies as well as in testing novel therapies for human ESCC.

Effects of bamboo leaf extract on growth performance, meat quality, and meat oxidative stability in broiler chickens.

This study was conducted to investigate the effects of dietary bamboo leaf extract (BLE) on growth performance, meat quality, oxidative stability, and nuclear factor erythroid 2-related factor 2 (Nrf2) related gene expression of breast meat in broilers. A total of 576 one-day-old male Arbor Acres broilers were divided into 6 groups. The control group (CTR) was fed basal diet, while BLE1, BLE2, BLE3, BLE4, and BLE5 were fed basal diet supplemented with 1.0, 2.0, 3.0, 4.0, and 5.0 g BLE per kg feed, respectively. Compared with the CTR group, BLE2 and BLE5 increased average daily feed intake from 1 to 21 D and 22 to 42 D (P < 0.05), BLE1 and BLE2 improved average daily gain (ADG) and feed to gain ratio from 22 to 42 D (P < 0.05). Throughout the trial period, the highest body weight and favorable ADG and feed to gain ratio were observed in the BLE2 group. The drip loss at 24 h and pH at 45 min postmortem of breast meat were linearly improved by BLE supplementation (P < 0.05). Shear force was significantly lower in BLE2 and BLE3 than that in CTR group. Increasing supplementation of BLE linearly improved free radical scavenging capacity and decreased malondialdehyde content of breast meat during 12 D of storage (P < 0.05). Total antioxidant capacity and glutathione peroxidase activity were linearly increased by BLE supplementation (P < 0.05). Compared with the CTR group, the mRNA expression of Nrf2 and glutathione peroxidase in BLE3, BLE4, and BLE5 groups was significantly promoted, and glutathione S-transferase gene expression was increased in BLE2, BLE4, and BLE5 (P < 0.05). The highest (P < 0.05) heme oxygennase-1 gene expression was observed in BLE5. In conclusion, broiler supplemented with BLE improved growth performance and meat quality, BLE supplementation might activate Nrf2 pathway to alleviate lipid oxidation and increase antioxidant capacity of breast meat. The dosage of 2.0 to 3.0 g/kg BLE in broiler diet was recommanded.

Effect of supplemental fermented Ginkgo biloba leaves at different levels on growth performance, meat quality, and antioxidant status of breast and thigh muscles in broiler chickens.

The present study was conducted to investigate the influence of dietary supplementation with different levels of fermented Ginkgo biloba leaves (FGBL) on growth performance, slaughter performance, meat quality, antioxidant enzyme capacity, and free radical scavenging activities of muscles in broiler chickens. A total of 648 one-d-old broiler chickens were randomly allocated into six dietary treatments, including control group (CON group: basal diet), FGBL1, FGBL2, FGBL3, FGBL4, and FGBL5 groups (basal diet containing 1.5, 2.5, 3.5, 4.5, and 5.5 g/kg FGBL, respectively). Body weight gain and feed intake were recorded at 1, 21, and 42 d. At 42 d, 2 birds from each replicate were slaughtered. The results indicated that 3.5 g/kg FGBL diet significantly increased (P < 0.05) ADFI and ADG in 1 to 42 d and ADFI in 22 to 42 d compared with the CON group. In 1 to 21 d, 4.5 g/kg FGBL diet improved (P < 0.05) ADFI and ADG. With dietary FGBL increasing, the feed: gain ratio (F/G) in 1 to 21 d was significantly decreased (P < 0.05). However, birds fed with 5.5 g/kg FGBL had a higher (P < 0.05) F/G compared with other groups in 22 to 42 d and 1 to 42 d. In addition, FGBL3 and FGBL4 showed lower (P < 0.05) L* value in breast muscle, cooking loss in thigh muscle and lower 24 h and 48 h drip loss in both breast and thigh muscles than those of other groups. Furthermore, birds in the FGBL3 and FGBL4 groups increased (P < 0.05) the activity of total superoxide dismutase and total antioxidant capability in muscles, and the scavenging activities of 2,2΄-azino-bis (3-ethylbenzothiazoline-6-sulfonic) acid radical, OH•, and O2•- in thigh muscle, decreased (P < 0.05) malondialdehyde concentration in thigh muscle, as compared to the CON group. In conclusion, FGBL had the potential to improve the growth performance, meat quality and antioxidant status of broiler chickens. The optimal dose in the present study of FGBL in broiler diets was from 3.5 to 4.5 g/kg.

Occurrence of Anguillicola crassus (Nematoda: Dracunculoidea) in Japanese eels Anguilla japonica from a river and an aquaculture unit in SW Taiwan.

The infection by swimbladder nematodes of the genus Anguillicola (Dracunculoidea: Anguillicolidae) was examined in 2 populations of the Japanese eel Anguilla japonica in SW Taiwan. Wild eels from the Kao-Ping river were compared with cultured eels from an adjacent aquaculture unit. Only the cosmopolitan species Anguillicola crassus was present. Among wild eels, prevalence of infection varied between 21 and 62%, and mean intensity between 1.7 and 2.7 for adult worms. Similar intensity values (1.3 to 2.8) were recorded for the larvae. In cultured eels, prevalence as well as mean intensities were higher. In the cultured hosts, mean larval intensities exceeded those of adult worms 2-fold, and maximum larval intensities were 4- to 5-fold higher than in eels from the river. In cultured eels, dead larvae were also more abundant than in wild eels. We conclude that infrapopulations of A. crassus in Japanese eels are regulated by the defense system of this host, intraspecific density-dependent regulation being less likely as the major regulatory mechanism. No influence of the parasite on eel condition was found in either wild or cultured eels, indicating a low or moderate pathogenic effect of A. crassus on this host. This study shows that A. crassus is moderately common in cultured and wild Japanese eels in Taiwan, where the parasite is endemic.

[Study on the LMCT band of zinc-bovine serum albumin].

The structure of metal centre in 1:1 zinc-bovine serum albumin complexes have been studied with UV spectrum. The data from literature is used to calculate the optical electronegativity of three pi orbits of histidyl imidazole. Using these data, we infer that two charge transition bands of complex of zinc ions and bovine serum albumin come from transition of pi 2, pi 3 electrons of histidyl imidazole to zinc ions.

A 140-kilodalton protein is released from cultured astrocytes by phosphatidylinositol phospholipase C.

Astrocytes in culture synthesize a 140-kilodalton (140-kD) protein (protein 140) that is released into the medium on incubation with phosphatidylinositol phospholipase C. This molecule therefore belongs to the class of proteins anchored to the external side of the cell membrane through a glycolipid moiety. Protein 140 is present in astrocyte cultures derived from two different regions of the brain and is not expressed by neurons in vitro. It differs from neuronal cell adhesion molecule 120 or 140 and is probably identical to a protein of 140 kD present in C6 glioma cells.

Measurements of the cross section for e(+)e(-) --> hadrons at center-of-mass energies from 2 to 5 GeV.

We report values of R = sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->mu(+)mu(-)) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.