Association of environmental cadmium exposure and bone remodeling in women over 50 years of age.

Chronic cadmium (Cd) toxicity is a significant health concern, and the mechanism of long-term low-dose Cd exposure on bone has not been fully elucidated yet. This study aimed to assess the association between long-term environmental Cd exposure and bone remodeling in women who aged over 50. A total of 278 non-smoking subjects from Cd-polluted group (n = 191) and non-Cd polluted group (n = 87) were investigated. Bone mineral density (BMD), the levels of three bone turnover markers (BTMs), including total procollagen type 1 amino-terminal propeptide (P1NP), collagen type 1 cross-linked C-telopeptide (ß-CTX), bone-specific alkaline phosphatase (BALP), together with serum soluble receptor activator of nuclear factor-κB ligand (sRANKL) and osteoprotegerin (OPG) were determined. Early markers of renal dysfunction were measured as well. Urinary Cd concentrations ranged from 0.41 to 87.31 µg/g creatinine, with a median of 4.91 µg/g creatinine. Age, BMD, T-score, and prevalence of osteoporosis showed no statistical differences among the quartiles of urinary Cd concentrations, while serum levels of P1NP, ß-CTX, and OPG were higher in the upper quartiles. Multivariate linear regression models indicated significantly positive associations of urinary Cd concentration with serum levels of P1NP, ß-CTX, BALP, sRANKL, and OPG. A ridge regression analysis with T-score and the three BTMs, sRANKL, and OPG, adjusted for age and body mass index (BMI), indicated that except for age and Cd exposure, ß-CTX was a predictor of T-score. These findings demonstrated that Cd may directly accelerate bone remodeling. Serum ß-CTX might be an appropriate biochemical marker for evaluating and monitoring Cd-related bone loss. Capsule: Cadmium (Cd) may directly accelerate bone remodeling and serum ß-CTX is a valuable biochemical marker for evaluating Cd-related bone loss.

Benefit-risk assessment of commonly consumed fish species from South China Sea based on methyl mercury and DHA.

Even though a growing number of reports indicated favorable health effects with fish consumption, kinds of hazardous substances in fish were detected in fish and to be exceeded advisory limitation. Benefit-risk assessment of commonly consumed fish is urgently needed. We conducted fish consumption survey and fish sampling in the coast of South China Sea to assess benefit-risk effect of commonly consumed fish species. For local residents, weekly methyl mercury (MeHg) exposures from commonly consumed fish species ranged from 0.12 to 2.11 µg/kg bw. Apart from Muraenesox cinereus and Acanthopagrus latus, the rest of 92% (23/25) fish species were at low risk of MeHg exposure. Daily docosahexaenoic acid intakes via consuming specific fish were between 42.18 and 1687.04 mg/day. A total of 72% (18/25) fish species could provide 200 mg/day of DNA for local residents. Benefit-risk assessment assuming intelligence quotient (IQ) score model showed net IQ point gains between 1.53 and 5.65 points with consuming various fish species, indicative of large distinction of health benefit from various fish species. This study suggests commonly consumed fish species from China South Sea could bring much more positive effect than negative effect. Species-specific fish should be considered when providing recommendations of fish consumption. Muraenesox cinereus and Acanthopagrus latus should be minded with risk of MeHg exposure in taking large amounts.

Health Risk Assessment for Local Residents from the South China Sea Based on Mercury Concentrations in Marine Fish.

The offshore area of the South China Sea is an important fishing ground in China. We used a food frequency questionnaire to determine marine fish consumption by local residents, and we detected mercury concentrations in commonly consumed marine fish species. In total, 127.9 g/day of the marine fish consumed was identified in 178 local residents. THg and MeHg concentrations in 209 samples of 22 fish species ranged from 11.3 to 215.0 µg/kg wt and 2.0 to 160.0 µg/kg wt, respectively. The mean MeHg exposure from marine fish to local residents was 0.099 µg/kg bw, accounting for 43.0% of the provisional tolerated weekly intake (PTWI) (1.6 µg/kg bw/week), suggesting a low health risk. However, a potentially high health risk (202.2% of PTWI) was identified in those with 97.5% MeHg exposure.

Bone morphogenetic protein 4 is involved in cadmium-associated bone damage.

Cadmium (Cd) is a well-characterized bone toxic agent and can induce bone damage via inhibiting osteogenic differentiation. Bone morphogenetic protein (BMP)/SMAD signaling pathway can mediate osteogenic differentiation, but the association between Cd and BMP/SMAD signaling pathway is yet to be illuminated. To understand what elements of BMPs and SMADs are affected by Cd to influence osteogenic differentiation and if BMPs can be the biomarkers of which Cd-induced osteoporosis, human bone marrow mesenchymal stem cells (hBMSCs) were treated with cadmium chloride (CdCl2) in vitro to detect the expression of BMPs and SMADs, and 134 subjects were enrolled to explore if the BMPs can be potential biomarkers of Cd-associated bone damage. Our results showed that Cd exposure significantly promoted the adipogenic differentiation of hBMSCs and inhibited its osteogenic differentiation by inhibiting the expression of BMP-2/4, SMAD4, and p-SMAD1/5/9 complex. And mediation analyses yielded that BMP-4 mediated 39.32% (95% confidence interval 7.47, 85.00) of the total association between the Cd and the risk of Cd-associated bone damage. Moreover, during differentiation, BMP-4 had the potential to enhance mineralization compared with CdCl2 only group. These results reveal that BMP-4 can be a diagnostic biomarker and therapeutic target for Cd-associated bone damage.

Curcumin-mediated photodynamic treatment extends the shelf life of salmon (Salmo salar) sashimi during chilled storage: Comparisons of preservation effects with five natural preservatives.

The impact of curcumin-mediated photodynamic treatment (PDT) on the microbiological, physicochemical and sensory qualities of salmon sashimi has not been explored. Herein, this study aimed to evaluate the effects of PDT on the shelf-life quality of ready-to-eat salmon fillets during chilled storage (4 °C) in comparison with five widely investigated natural extracts, including cinnamic aldehyde, rosmarinic acid, chlorogenic acid, dihydromyricetin and nisin. From a microbial perspective, PDT exhibited outstanding bacterial inhibition, the results of total viable counts, total coliform bacteria, psychrotrophic bacteria, Pseudomonas spp., Enterobacteriaceae family, and H2S-producing bacteria were notably inactivated (p < 0.05) to meet the acceptable limits by PDT in comparison with those of the control group and natural origin groups, which could extend the shelf-life of salmon fillets from<6 days to 10 days. In the alteration of physicochemical indicators, PDT and natural extracts were able to maintain the pH value and retard lipid oxidation in salmon fillets, while apparently slowing the accumulation (p < 0.05) of total volatile basic nitrogen and biogenic amines, especially the allergen histamine, which contrary to with the variation trend of spoilage microbiota. In parallel, PDT worked effectively (p < 0.05) on the breakdown of adenosine triphosphate and adenosine diphosphate to maintain salmon fillet freshness. Additionally, the physical indicators of texture profile and color did not have obvious changes (p < 0.05) after treated by PDT during the shelf life. Besides, the sensory scores of salmon samples were also significantly improved. In general, PDT not only has a positive effect on organoleptic indicators but is also a potential antimicrobial strategy for improving the quality of salmon sashimi.

Prediction of ocular irritancy of 26 chemicals and 26 cosmetic products with isolated rabbit eye (IRE) test.

OBJECTIVE: This study aims to establish and evaluate the methodology of isolated rabbit eye (IRE) test. METHODS: IRE test was performed according to modifications of the in vitro toxicology (INVITTOX) Protocol No.85: Rabbit enucleated eye test by European Centre for the Validation of Alternative Methods (ECVAM), and then 26 chemicals and 26 cosmetic products were tested in both in vitro IRE and in vivo Draize tests. A statistical analysis was conducted to determine the relevance of the IRE test to the data generated in the Draize test. RESULTS: IRE test was established successfully in our laboratory. It was shown that ranking correlation and class concordance were fairly well between the IRE test and the Draize test for 26 reference chemicals (Fisher's Exact Test χ(2)=51.314, P<0.001; McNemar P=0.261; Gamma=0.960, P<0.001; Kappa=0.843, P<0.001) and 26 cosmetic products (Fisher's Exact Test χ(2)=15.522, P<0.001; McNemar P=0.311; Gamma=0.967, P<0.001; Kappa=0.611, P<0.001). CONCLUSION: IRE test was established successfully for in vitro testing of eye irritation as an alternative to Draize test.

Recent advancement of bioinspired nanomaterials and their applications: A review.

With the advancement in the field of nanotechnology, different approaches for the synthesis of nanomaterials have been formulated, among which the bioinspired or biomimetic nanoplatforms have been utilized for different biomedical applications. In this context, bioinspired or biomimetic nanoparticles (NPs) have been synthesized in which the inspiration for synthesis is taken from nature or its components. Innovations in bioengineering tools and bio-conjugation chemistry have enabled scientists to develop novel types of such nanoplatforms. They have several advantages over normal synthesis protocols. In this review, we 1) summarized nanomaterial types and their advancements in bioinspired nanotechnology therapies; 2) discussed the major types, novel preparation methods, and synthesis progress of NPs in current biomedical fields; 3) gave a brief account of the need for synthesizing NPs via a bioinspired route rather than their common route; 4) highlighted the updated information on the biomimetic synthesis of different types of NPs; and 5) provided future perspectives in the synthesis of novel NPs for their potential applications in biomedical sciences.

[Influence of joint exposure to diazinon, propoxur and bisphenol A on phagocytosis of RAW264.7 cell].

OBJECTIVE: To explore the toxicity of joint exposure to diazinon, propoxur and bisphenol A on phagocytosis. METHODS: Flow cytometer was employed to detect the influence of diazinon and bisphenol A, propoxur and bisphenol A in mixture (mixed according to ratio of IC(50)) on mouse macrophage RAW264.7 cells' function to phagocyte fluorescent microspheres, adopting the percentage of phagocytic cells (PP) and the phagocytic index (PI) as measurement indicators. The final concentrations of mixture of diazinon and bisphenol A were (0.4 + 0.1), (3.6 + 0.7), (36.2 + 7.2), (43.4 + 8.7), (52.1 + 10.4), (62.5 + 12.5), (75.0 + 15.0) µg/ml; while those of mixture of propoxur and bisphenol A were (0.2 + 2.0 × 10(-2)), (2.4 + 0.2), (23.7 + 2.0), (35.6 + 3.0), (53.3 + 4.4), (80.0 + 6.7), (120.0 + 10.0) µg/ml. Then based on the dose-response relationship, a 2 × 2 factorial design was then carried out among different doses of mixture with statistical significance to statistically evaluate the interaction between diazinon and bisphenol A, propoxur and bisphenol A. RESULTS: After the joint exposure, compared to the control group (PP = (23.6 ± 2.2)%; PI = 0.36 ± 0.03), any dose of the mixture of diazinon and bisphenol A ((52.1 + 10.4), (62.5 + 12.5), (75.0 + 15.0) µg/ml) could significantly increase the levels of PP ((29.0 ± 1.4)%, t = 3.89, P < 0.05; (30.2 ± 2.3)%, t = 4.74, P < 0.05; (35.0 ± 3.4)%, t = 8.21, P < 0.05) and PI (0.43 ± 0.03, t = 3.86, P < 0.05; 0.41 ± 0.02, t = 2.95, P < 0.05; 0.46 ± 0.03, t = 5.34, P < 0.05); while that of propoxur and bisphenol A ((35.6 + 3.0), (53.3 + 4.4), (80.0 + 6.7), (120.0 + 10.0) µg/ml) reduced the levels of PP ((20.6 ± 1.1)%, t = -3.00, P < 0.05; (20.2 ± 1.0)%, t = -3.42, P < 0.05; (19.4 ± 1.3)%, t = -4.23, P < 0.05; (18.8 ± 2.1)%, t = -4.81, P < 0.05) and PI (0.31 ± 0.01, t = -4.75, P < 0.05; 0.31 ± 0.01, t = -4.58, P < 0.05; 0.30 ± 0.01, t = -4.92, P < 0.05; 0.27 ± 0.02, t = -7.80, P < 0.05) on the contrary. The 2 × 2 factorial design was carried out between the mixture of diazinon (60.0 µg/ml; PP = (28.5 ± 3.4)%; PI = 0.49 ± 0.07) and bisphenol A (12.0 µg/ml; PP = (35.7 ± 2.7)%; PI = 0.67 ± 0.07), and the mixture of propoxur (48.0 µg/ml ; PP = (28.1 ± 2.2)%; PI = 0.48 ± 0.04) and bisphenol A (4.0 µg/ml; PP = (34.4 ± 2.7)%; PI = 0.59 ± 0.07). The mixture of diazinon and bisphenol A (PP = (30.4 ± 1.4)%, F(interaction) = 6.22, P < 0.05; PI = 0.53 ± 0.03, F(interaction) = 7.35, P < 0.05) and the mixture of propoxur and bisphenol A (PP = (27.5 ± 4.1)%, F(interaction) = 4.56, P < 0.05; PI = 0.46 ± 0.08, F(interaction) = 11.13, P < 0.05) both showed a significant antagonistic interaction on phagocytosis of RAW264.7 cell. CONCLUSION: It is suggested that the interactions between diazinon & bisphenol A and propoxur & bisphenol A both played the antagonistic role on phagocytic function of macrophages in vitro.

[Study on alternative methods for the acute oral toxicity in detection of chemicals].

OBJECTIVE: To evaluate three alternative methods for LD50 test-Fixed Dose Procedure (FDP), the Acute Toxic Class Method (ATC) and Up and Down Procedure (UDP). METHODS: Female SD rats (8-12 weeks of age, 160-200 g) were used. Three alternative methods from OECD were applied to assess 22 chemicals (10 cosmetic raw materials and 12 raw materials of personal and home care products). The toxicity ranking for tested chemicals was established according to Globally Harmonized System (GSH). The results LD50 test were compared for the consistency and correlation between alternative methods and traditional test. RESULTS: For cosmetic raw materials, the concordance rate of the three alternative methods was 80% (8/10); for raw material of personal and home care products, the concordance rates of FDP, ATC and UDP was 91.7% (11/12), 75.0% (9/12) and 83.0% (10/12), respectively. The number of animals required in three alternative methods was significantly lower than that in traditional test (P < 0.05), but the time required in three alternative methods was significantly higher than that in traditional test (P < 0.05). CONCLUSIONS: High consistency and correlation were found between each alternative method and LD50 test. FDP may be more potential when applied to assess acute oral toxicity of cosmetic raw materials.

Subacute toxicity of mesoporous silica nanoparticles to the intestinal tract and the underlying mechanism.

The biological safety of mesoporous silica nanoparticles (MSNs) has gradually attracted attention. However, few studies of their toxicity to the intestine and mechanism are available. In this study, their primary structures were characterized, and their subacute toxicity to mice was investigated. After 2 weeks of intragastric administration of MSNs, they significantly enhanced serum ALP, ALT, AST and TNF-α levels and caused infiltration of inflammatory cells in the spleen and intestines. MSNs induced intestinal oxidative stress and colonic epithelial cell apoptosis in mice. Intestinal epithelial cells exhibited mitochondrial ridge rupture and membrane potential decrease after MSN treatment. Additionally, MSNs increased ROS and NLRP3 levels and inhibited expression of the autophagy proteins LC3-II and Beclin1. MSNs significantly changed the intestinal flora diversity in mice, especially for harmful bacteria, leading to intestinal microecology imbalance. Meanwhile, MSNs influenced the expression of metabolites, which were involved in a range of metabolic pathways, including pyrimidine metabolism, central carbon metabolism in cancer, protein digestion and absorption, mineral absorption, ABC transport and purine metabolism. These results indicated that the subacute toxicity of mesoporous silicon was mainly caused by intestinal damage. Thus, our research provides additional evidence about the safe dosage of MSNs in the clinical and food industries.

Occurrence and dietary exposure assessment of pentachlorophenol in livestock, poultry, and aquatic foods marketed in Guangdong Province, China: Based on food monitoring data from 2015 to 2018.

As a persistent organic pollutant, pentachlorophenol (PCP) has serious impacts on human health. However, its presence in animal source food products sold in the Guangdong Province (GD) of China, and the resultant dietary exposure have not been elucidated. To address this gap, 3,100 samples from seven food categories, including beef, pork, mutton, offals, broilers, hen eggs, and farmed freshwater fish, marketed throughout four geographical regions of GD, were collected from 2015 to 2018. Gas chromatography coupled with mass spectrometry was employed to detect PCP levels in these food matrices. PCP was found in all food categories, but the average contamination levels were low, ranging from 0.40 µg/kg wet weight (ww) (hen eggs) to 5.85 µg/kg ww (offals). However, higher concentrations of PCP were detected (P < 0.05) in animal source food from the North region. Additionally, a temporal declining trend was observed in this four-year consecutive survey. The estimated human dietary exposure of PCP to population groups, including the general population and subgroups (male and female, children, and adults), was found to be far below the permissible daily intake (3 µg/kg body weight). Therefore, the health impacts of PCP should be correspondingly low for local residents, based on current toxicological knowledge. Regional exposure patterns varied due to different extents of contamination in the four areas, and pork, broilers, and freshwater fish were the major sources of dietary PCP exposure. PRACTICAL APPLICATION: As a persistent organic pollutant, pentachlorophenol (PCP) has serious impacts on human health. However, its presence in animal source food products sold in Guangdong Province of China, and the resultant dietary exposure have not been elucidated. In this study, we conducted an in-depth investigation on the occurrence of PCP in major foodstuff categories, including beef, pork, mutton, broilers, offals, hen eggs, and farmed freshwater fish, marketed in all 21 prefecture-level divisions of Guangdong Province, in order to provide integral insights for regulatory authorities.

Bioaccessibility and bioavailability adjusted dietary exposure of cadmium for local residents from a high-level environmental cadmium region.

The critical health risks caused by cadmium (Cd) via dietary exposure are commonly assessed by detecting Cd concentrations in foods. Differently, in this study, the bioaccessibility and bioavailability of Cd in major local harvests were introduced to assess the dietary exposure of local residents from a high-level environmental Cd region. The results indicated that certain Cd was released into the digestive juice after in vitro digestion with a bioaccessibility of 20-63% for rice and 3-32% for leafy vegetables, and the released portion was partially absorbed by Caco-2 cells with a bioavailability of 2-21% for rice and 0.2-13% for leafy vegetables. The results obtained from the toxicokinetic model revealed that the predicted urinary Cd values from the estimated daily intake (EDI) of Cd, which accounted for bioaccessibility and bioavailability, were consistent with the actual measured values, and the EDIs were considerably lower than the acceptable daily intake. This suggests that the bioaccessibility and bioavailability adjusted dietary Cd exposure should be more precise. The key issues addressed in our study implores that a potential health risk cannot be neglected in people with high consumption of rice from high-level zone.

Prevalence of anxiety and depression symptom, and the demands for psychological knowledge and interventions in college students during COVID-19 epidemic: A large cross-sectional study.

BACKGROUND: Although studies have suggested experiencing the epidemic of severe infectious diseases increased the prevalence of mental health problems, the association between COVID-19 epidemic and risk of anxiety and depression symptom in college students in China was unclear. METHODS: A large cross-sectional online survey with 44,447 college students was conducted in Guangzhou, China. The Zung's Self-rating Anxiety Scale (SAS) and the Center for Epidemiologic Studies Depression Scale (CES-D Scale) were used to define the anxiety and depression symptom, respectively. Multivariable logistic regression models were used to analyze the association between COVID-19 epidemic and risk of anxiety and depression symptom. RESULTS: The prevalence of anxiety and depression symptom was 7.7% (95% confidence interval [CI]: 7.5%, 8.0%) and 12.2% (95%CI: 11.9%, 12.5%), respectively. Compared with students who reported have not infected or suspected cases in family members and relatives, students who reported having confirmed (OR=4.06; 95%CI: 1.62, 10.19; P = 0.003), and suspected (OR=2.11; 95%CI: 1.11, 4.00; P = 0.023) cases in family members and relatives had higher risk of depression symptom. Additionally, the proportions of students with anxiety and depression symptom reported more demand of psychological knowledge and interventions than those without (P<0.001). LIMITATIONS: All the data in this study was collected through online questionnaire, and we did not evaluate the reliability and validity. CONCLUSIONS: The prevalence of anxiety and depression symptom was relatively low in college students, but the COVID-19 epidemic-related factors might be associated with higher depression symptom risk.

[Molecular characters of epidemic cerebrospinal W135 Neisseria meningitidis strain firstly isolated in Guangdong province].

OBJECTIVE: To analyze the molecular characters of the W135 Neisseria meningitidis strain firstly isolated from patients in Guangdong province. METHODS: Biochemical profile by using the API NH system (bio-Merieux, France) was used for confirmation,and sero-grouping of the meningococcal isolates including one serogroup W135, one serogroup C and three serogroups of a Neisseria meningitidis isolated from patients in Guangdong province in recent two years were performed. The subtype was determined after amplifying porA and porB respectively from the genome DNA of Neisseria meningitidis. Multilocus sequence typing (MLST) was performed for determining the allele profiles and the sequence types (STs). The polygenetic tree was obtained by analyzing the allele profiles with program Splits tree online. The molecular characters of the serogroup W135 Neisseria meningitidis was analyzed by its evolution relationship and the variable regions in porA and porB which encoding the outer membranes proteins (OMPs). RESULTS: The subtype determined by porA variable regions of the serogroup W135 Neisseria meningitidis was P1.5,2, which was one of the most invasive types. The types of variable regions (VRs) I, IV, V, VII with porB were 1, 1, 1, 17, and there was no VI and VIII in porB. The allele profile of the W135 strain in this study was 2, 123, 4, 3, 8, 4, 6, and its sequence type was ST-2960, which belonged to ST-11/ET-37 clone complex. The subtypes of the serogroup C and serogroup A strains were P1.20, while their types of VR IV were all 7, and they all hadn't VR VII in porB. The strain serogroup C belonged to ST-4821 clone complex, and the 3 serogroup A strains belonged to ST-5 clone complex. CONCLUSION: The molecular character of the serogroup W135 Neisseria meningitidis should be the same with the strains isolated in foreign country, and be different from the epidemic types in the area. This serogroup W135 Neisseria meningitis isolated from patients in Guangdong for the first time was thought to be a new type appearing in the local area.

Low-dose cadmium exposure acts on rat mesenchymal stem cells via RANKL/OPG and downregulate osteogenic differentiation genes.

Chronic cadmium (Cd) toxicity is a significant health concern, and the mechanism of long-term low-dose Cd exposure on bone has not been fully elucidated till date. This study aimed to assess the association between rat mesenchymal stem cells (MSCs) and long-term Cd exposure through 38-week intake of CdCl2 at 1 and 2 mg/kg body weight (bw). Increased gene expression of receptor activator of NF-κB ligand (RANKL) and decreased gene expression of osteoprotegerin (OPG) were observed. Fold change of RANKL gene expression (fold change = 1.97) and OPG gene expression (fold change = 1.72) showed statistically significant differences at dose 2 mg/kg bw. Decreased expression of key genes was observed during the early osteogenic differentiation of MSCs. The gene expression of Osterix in 1 mg/kg bw group was decreased by 3.70-fold, and the gene expressions of Osterix, Osteopontin, collagen type I alpha 2 chain (COL1a2) and runt-related transcription factor 2 (RUNX2) in 2 mg/kg bw group were decreased by 1.79, 1.67, 1.45 and 1.35-folds, respectively. Exposure to CdCl2 induced an increase in the renal Cd load, but only an adaptive response was observed, including increased expression of autophagy-related proteins LC3B and Beclin-1, autophagy receptor p62, and heme oxygenase 1 (HO-1), which is an inducible isoform that releases in response to stress. There were no significant changes in the urinary low molecular weight proteins including N-acetyl-b-D-glucosaminidase (NAG), ß2-microglobulin and albumin (U-Alb). Urinary calcium (Ca) excretion showed no increase, and no obvious renal histological changes. Taken together, these results indicated that the chronic CdCl2 exposure directly act on MSCs through RANKL/OPG pathway and downregulate the key genes involved in osteogenic differentiation of MSCs. The toxic effect of Cd on bone may occur in parallel to nephrotoxicity.

[Relationship between apoptosis and activity of protein kinase B in adrenocortical cells induced by cadmium chloride].

OBJECTIVE: To study apoptosis induced by cadmium chloride (CdCl2) and the alteration in activity of protein kinase B (PKB/Akt) in adrenocortical cells. METHODS: Fasciculata-glomerulosa (FG) cells of male guinea pigs were dispersed and primarily cultured in vitro. Features of apoptotic cells were observed using combined labeling with annexin-V and propidium iodide (PI) and flow cytometry. The activity of PKB/Akt was determined with immunoprecipitation and the chemiluminescence assay. RESULTS: Apoptosis rate of FG cells increased with dose of CdCl2 two hours after treatment with 6.25-100.00 micromol/L of it, with significant difference in the groups treated with 25.00, 50.00, 100.00, micromol/L of CdCl2, as compared with the control group (P < 0.01). Regression analysis showed that occurrence of apoptosis correlated with the dose of CdCl2 in a dose-response pattern. In the meanwhile, there were obviously elevated percentages of apoptotic cells as the increase in duration of incubation ranging from 5.58% to 73.08% for incubating cells with 50.00 micromol/L of CdCl2, from 15 minutes to 4 hours. Duration of incubating cells with CdCl2 were correlated with occurrence of apoptosis in a time-effect manner. The gray scales of PKB/Akt were manifested to be decreased as the ascending of CdCl2 dosage from 6.25 to 200.00 micromol/L, with the linear correlation. CONCLUSION: 6.25 to 100.00 micromol/L CdCl2 might elicit apoptosis of adrenocortical cells. Meanwhile, PKB/Akt is decreased.

Levels, congener profiles, and dietary intake assessment of polychlorinated dibenzo-p-dioxins/dibenzofurans and dioxin-like polychlorinated biphenyls in beef, freshwater fish, and pork marketed in Guangdong Province, China.

Persistent organic pollutants such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) consisting of non-ortho and mono-ortho PCBs are suggested to be very hazardous and have adverse effects on human health. However, their levels and congener profiles in retail foods marketed in Guangdong Province of China have not been elucidated thus far. Thus, in this study, 226 individual samples of beef, freshwater fish, and pork marketed across four regions of Guangdong Province were randomly collected during 2013-2015 to determine their levels of PCDD/Fs and DL-PCBs. The results showed that the total toxic equivalency quantities (TEQs) of most samples were below the maximum limits except for the 26 samples collected from the vicinities of pollution areas. The median total TEQs of these three categories were 0.174, 0.488, and 0.113pgTEQ/g fw, respectively, which indicated that the contamination status of the studied foods was not serious. For congener profiles, significantly different patterns were observed in three food groups, but with the same major TEQ contributors being 2,3,4,7,8-PeCDF in beef, freshwater fish, and pork. Regional differences of congener profiles in each food group were also found in this study, which might be attributed to the regionally different distributions of PCDD/Fs and DL-PCBs in environment media. The dietary exposures of four population subgroups (girls, boys, male adults, and female adults) to PCDD/Fs and DL-PCBs via three food groups were estimated to assessed the potential risks. They were all lower than the provisional tolerable monthly intake (PTMI, 70pgTEQ/kgbw/month) established by Joint FAO/WHO Expert Committee on Food Additive. In these food categories, the exposure to PCDD/Fs and DL-PCBs via freshwater fish was the highest one, which accounted for about 20% of PTMI, indicating that it was the major route to expose dioxin compounds.

[The establishment and assessment on cosmetic products using 3T3 mouse fibroblast neutral red uptake phototoxicity assay].

OBJECTIVE: To establish the 3T3 mouse fibroblast neutral red uptake (NRU-PT) phototoxicity test method, and evaluate the practicality of the method in detecting potential phototoxicity of the cosmetic products. METHODS: Fifteen phototoxic and 9 non-phototoxic chemicals were tested in our laboratories, the phototoxic potential of the test chemicals was evaluated in a prediction model in which either the photo irritation factor (PIF) or the mean photo effect (MPE) was compared with the coherence and sensitivity of the method. 20 kinds of functional cosmetics were detected and the results were analyzed by the 3T3 NRU-PT in vitro and Guinea pig skin phototoxicity test (in vivo). RESULTS: Both PIF and MPE of the chemicals were highly reproduced, and the correlation between in vitro and in vivo data was almost perfect. All the non-phototoxic provided a negative result, while 14 of the 15 phototoxic tested chemicals gave clear positive results. For cosmetics, the correlation between in vitro and in vivo data was consistent. CONCLUSION: The 3T3 NRU PT test was established successfully, it should be used as a good alternative method for assessing the phototoxic potential of the chemicals and cosmetics in China.

[Study on the genetic polymorphisms of human glutathione-S-transferase A1 in Hakka population in South China].

OBJECTIVE: Glutathione-S-transferase A1 (GSTA1) is one of the major phase II detoxification enzymes in the cytosol, which genetic polymorphisms distribution is different in different ethnic, national and regional population. Up to now, GSTA1 genetic polymorphisms has been rarely reported in China. The purpose of the study was to investigate the distribution of genetic polymorphisms of human GSTA1 in Hakka population in South China. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were used to identify the genotypes of GSTA1 gene and the data were analyzed with SPSS10.0 software. RESULTS: The GSTA1 genetic polymorphisms were detected in 480 samples. The frequency of GSTA1 * A/ * A,GSTA1 * A/ * B and GSTA1 * B/ * B were 77.1%, 21.7% and 1.2% respectively. And the GSTA1 genetic polymorphism distribution was in accordance with the Hardy-Weinberg equilibrium rule. There were no difference in the GSTA1 genetic polymorphisms among the different groups of age or gender. Logistic regression analysis showed that there were no association between the GSTA1 genetic polymorphism and family history of hypertension, coronary heart disease, stroke, lung cancer and nasopharyngeal cancer, et al. CONCLUSION: The GSTA1 gene existed polymorphism among Hakka in South China.

[Effects of overexpression of human pol-beta on cellular response to DNA damage].

OBJECTIVE: To investigate the biological effects of overexpression of the human DNA polymerase (pol-beta) on cellular response to DNA damage. METHODS: The cell strain HLFbeta from the stable overexpression of the human pol-beta was contaminated with methyl methanesulfonate (MMS) for investigating the effects of the pol-beta on the cellular responses to DNA damage on the aspects such as the DNA damage, the cell cycle and the induced mutation rate. RESULTS: The cell HLFbeta from the stable overexpression of the human pol-beta was obtained through the screening. The cellular response to DNA damage of HLFbeta induced by the MMS in the intermediate and high dosage group (ranging from 0.5 to 0.8 mmol/L) was significantly lower than that in the control group. The analysis for the cell cycle distribution showed that both the two types of cells contaminated by MMS had retardation at G(2) phase. In the HLFbeta group, the cells had the obvious G(2) phase retardation and 49.0% of the cells were retarded at G(1) phase as well when the MMS was increased to 0.5 mmol/L while in the control, only 20.1% of the cells were retarded at the G(1) phase when the same dosage of MMS was administered. Moreover, the MMS-induced mutagenesis in HLFbeta was increased from 4.5 x 10(-6) to 8.2 x 10(-6), significantly higher than that in the control group (P < 0.05). CONCLUSION: High Pol-beta level decreases cellular DNA damage induced by MMS. Nevertheless, the overexpression of Pol-beta can also increase error-prone DNA synthesis during DNA repair process.