Long-term PM2.5 exposure disrupts corneal epithelial homeostasis by impairing limbal stem/progenitor cells in humans and rat models.

BACKGROUND: Limbal stem/progenitor cells (LSPCs) play a crucial role in maintaining corneal health by regulating epithelial homeostasis. Although PM2.5 is associated with the occurrence of several corneal diseases, its effects on LSPCs are not clearly understood. METHODS: In this study, we explored the correlation between PM2.5 exposure and human limbal epithelial thickness measured by Fourier-domain Optical Coherence Tomography in the ophthalmologic clinic. Long- and short-term PM2.5 exposed-rat models were established to investigate the changes in LSPCs and the associated mechanisms. RESULTS: We found that people living in regions with higher PM2.5 concentrations had thinner limbal epithelium, indicating the loss of LSPCs. In rat models, long-term PM2.5 exposure impairs LSPCs renewal and differentiation, manifesting as corneal epithelial defects and thinner epithelium in the cornea and limbus. However, LSPCs were activated in short-term PM2.5-exposed rat models. RNA sequencing implied that the circadian rhythm in LSPCs was perturbed during PM2.5 exposure. The mRNA level of circadian genes including Per1, Per2, Per3, and Rev-erbα was upregulated in both short- and long-term models, suggesting circadian rhythm was involved in the activation and dysregulation of LSPCs at different stages. PM2.5 also disturbed the limbal microenvironment as evidenced by changes in corneal subbasal nerve fiber density, vascular density and permeability, and immune cell infiltration, which further resulted in the circadian mismatches and dysfunction of LSPCs. CONCLUSION: This study systematically demonstrates that PM2.5 impairs LSPCs and their microenvironment. Moreover, we show that circadian misalignment of LSPCs may be a new mechanism by which PM2.5 induces corneal diseases. Therapeutic options that target circadian rhythm may be viable options for improving LSPC functions and alleviating various PM2.5-associated corneal diseases.

Assessment of radiation exposure and public health before and after the operation of Sanmen nuclear power plant.

Introduction: Sanmen nuclear power plant (SNPP) operates the first advanced passive (AP1000) nuclear power unit in China. Methods: To assess the radiological impacts of SNPP operation on the surrounding environment and the public health, annual effective dose (AED) and excess risk (ER) were estimated based on continuous radioactivity monitoring in drinking water and ambient dose before and after its operation during 2014-2021. In addition, the residents' cancer incidence was further analyzed through authorized health data collection. Results: The results showed that the gross α and gross ß radioactivity in all types of drinking water were ranged from 0.008 to 0.017 Bq/L and 0.032 to 0.112 Bq/L, respectively. The cumulative ambient dose in Sanmen county ranged from 0.254 to 0.460 mSv/y, with an average of 0.354 ± 0.075 mSv/y. There is no statistical difference in drinking water radioactivity and ambient dose before and after the operation of SNPP according to Mann-Whitney U test. The Mann-Kendall test also indicates there is neither increasing nor decreasing trend during the period from 2014 to 2021. The age-dependent annual effective doses due to the ingestion of drinking water or exposure to the outdoor ambient environment are lower than the recommended threshold of 0.1 mSv/y. The incidence of cancer (include leukemia and thyroid cancer) in the population around SNPP is slightly higher than that in other areas, while it is still in a stable state characterized by annual percentage changes. Discussion: The current comprehensive results show that the operation of SNPP has so far no evident radiological impact on the surrounding environment and public health, but continued monitoring is still needed in the future.

Assessment of neutrophil to lymphocyte ratio, C-reactive protein, mean platelet volume in obese, and nonobese patients with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is associated with low-grade chronic inflammation. This was a retrospective case-control study. In the present study, the risk coefficients of neutrophil to lymphocyte ratio (NLR), high-sensitive C-reactive protein (hs-CRP), and mean platelet volume (MPV) in obese patients with PCOS were determined. This study was designed to investigate NLR, hs-CRP, and MPV levels in 68 obese patients with PCOS and 44 nonobese patients with PCOS, and our study group was matched with 47 obese and 43 nonobese controls, respectively. PCOS group had higher MPV, NLR, insulin, glucose, and HOMA-IR rates than those of the controls. Subgroup analyses revealed that the obese PCOS group had higher NLR, hs-CRP, and MPV levels compared to those of controls. The obese PCOS group had higher NLR, hs-CRP, and MPV levels compared to those of the nonobese PCOS group. The odds ratios and 95% confidence intervals of those variables (NLR, hs-CRP, MPV) were found significant (P < .05). NLR, hs-CRP, and MPV variables were found statistically significant in the analysis of receiver operating characteristics. Our study demonstrated that NLR, hs-CRP, and MPV levels are increased in patients with obese PCOS.

Long-term investigation of environmental radioactivity levels and public health around the Qinshan Nuclear Power Plant, China.

To evaluate the impact of the Qinshan Nuclear Power Plant (Qinshan NPP) in normal operation on the surrounding environment and population, the radioactivity levels of drinking water and the ambient environment, as well as the residents' cancer incidence, were continuously monitored for a period of 9 years (2012-2020). All of the gross α and ß radioactivity concentrations in drinking water were less than the WHO recommended values (0.5 Bq/L for gross α and 1 Bq/L for gross ß). The results of ambient environment accumulated dose monitored by thermoluminescent dosimeters (TLDs) indicated that the ambient environment radioactive level around the Qinshan NPP is consistently at natural background radiation levels. The age-dependent annual effective doses due to the ingestion of tap water or exposure to the outdoor ambient environment are lower than the reference dose of 0.1 mSv/year. The corresponding excess risks are at relatively low levels. Thus, the consumption of drinking water and outdoor activities are not expected to give rise to any detectable adverse effects on the health of the public around the Qinshan NPP. For all cancers combined, the age-standardized incidence rate by the Chinese 2000 standard population of the inhabitants living around Qinshan NPP is consistent with that of Zhejiang Province as a whole. Based on current radiation risk estimates, radiation exposure is not a plausible explanation for any excess cancers observed in the vicinity of the Qinshan NPP.

Elevated cadmium and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in residents living near electroplating industries.

This study aims to evaluate the body burdens of cadmium (Cd) associated with potential health impairment in residents living near electroplating industries. A total of 269 residents from exposure area and 106 from control area were recruited. We measured the blood and urinary Cd levels using an inductively coupled plasma mass spectrometer (ICP-MS); performed physical examinations; determined the urinary levels of ß2-microglobulin (ß2-MG), Nacetyl-ß-D-glucosaminidase (NAG), and 8-hydroxy-2'-deoxyguanosine (8-OHdG); and evaluated the associations between Cd and these biomarkers. Blood and urinary Cd levels in exposure group were statistically higher than in control group (1.712 vs. 1.159 µg/L; 1.980 vs. 1.740 µg/L, respectively, p < 0.05). Urinary ß2-MG and 8-OHdG levels in exposure group were also statistically higher (0.448 vs. 0.090 mg/L; 12.759 vs. 12.115 µg/L, respectively, p < 0.05), but urinary NAG levels showed no significant difference between the two groups (13.614 vs. 8.246 IU/L, p > 0.05). The proportion of abnormal nasal symptoms occurring in exposed subjects (88.8%) was much higher than in control subjects (78.2%, p < 0.05). Urinary Cd levels were positively correlated with blood Cd levels, urinary 8-OHdG, and NAG levels (r = 0.307, r = 0.185, r = 0.150, p < 0.05), but not correlated with urinary ß2-MG levels (p > 0.05). In conclusion, our study revealed that residents living in close proximity to electroplating industries had elevated body burdens of Cd levels, as well as slight renal dysfunction and DNA oxidation damage.

Geographical influences on thyroid abnormalities in adult population from iodine-replete regions: a cross-sectional study.

The studies on the increasing incidence of thyroid abnormalities are scarce. The aim of this current study was to ascertain the effects of geographical region on thyroid abnormalities under the context of universal salt iodization (USI). We randomly selected 1255 participants residing in inland and 1248 in coast, with the determination of urinary iodine concentration (UIC) and functional and morphological abnormalities of thyroid gland. The median UIC was significantly higher for the inland participants (188.5 µg/L) than the coastal participants (128.5 µg/L; p < 0.001), indicating iodine sufficiency in both populations according to the recommended assessment criteria by the World Health Organization. However, the spectrum of thyroid abnormalities varied between regions, with hypothyroidism prevalent in inland and thyroid nodules in coast. The associations between region and thyroid abnormalities via binary logistic regression models showed that the coastal participants were at a higher risk of total thyroid abnormalities than those from the inland (OR 1.216, 95% CI 1.020-1.449), after the adjustment of ten confounders (demographical characteristics, smoking status, metabolism syndrome, and hyperuricemia). These results indicated that further investigations of the adverse effects of hypothyroidism and thyroid nodules on health burden is urgently needed to sustain USI program.

Integrative Analysis of DNA Methylation and Gene Expression Identified Follicular Thyroid Cancer-Specific Diagnostic Biomarkers.

The diagnosis of follicular thyroid carcinoma (FTC) prior surgical resection remains a challenge, as routine screening methods, such as ultrasound or even FNAB, could not diagnose FTC preoperatively. Here, we performed an integrative analysis of DNA methylation and RNA array data from our own cohort (14 Follicular thyroid carcinoma vs 16 Benign thyroid lesion) to identify thyroid cancer-specific DNA methylation markers. We first identified differentially methylated and expressed genes and examined their correlations. Candidate DNA methylation sites were selected and further verified in validation set. Among all candidate methylation sites, cg06928209 was the most promising site as a molecular marker for early diagnosis, with a sensitivity of 90%, a specificity of 80% and an AUC of 0.77. Overall, our study demonstrates the potential use of methylation markers in FTC diagnosis and may boost the development of new epigenetic therapies.

Personal exposure to PM2.5-bound heavy metals associated with cardiopulmonary function in general population.

To better understand the cardiopulmonary alterations associated with personal exposed PM2.5-bound heavy meals, we conducted a cross-sectional study in 2018 on 54 general residents. For each subject, PM2.5 exposure filter was collected by a low-volume sampler for 24 h; blood and urine samples were collected subsequently. Heavy metals in PM2.5, blood, and urine samples were determined by inductively coupled plasma mass spectrometry method. PM2.5-bound Mn, Cd, Sb, Pb, and Ni levels were 20.5, 9.27, 9.59, 28.3, and 16.9 ng/m3, respectively. The distribution of these metals followed the order: Pb (33.47%) > Mn (24.24%) > Ni (19.99%) > Sb (11.34%) > Cd (10.96%). The distribution of heavy meals in PM2.5, blood, and urine differed from each other. PM2.5-bound Cd, Pb levels were positively correlated with blood Cd, Pb levels (r = 0.323, r = 0.334, p < 0.05), respectively. PM2.5-bound Cd level was significantly higher in smoking group than non-smoking group (28.8 vs. 7.27 ng/m3, p < 0.01), same as Sb level (12.0 vs. 9.34 ng/m3, p < 0.01). Cd and Pb exposure might interact with cardiovascular function through autonomic regulation. No significant correlation was observed between metal exposure and pulmonary function. In conclusion, our data suggested that personal exposure to specific PM2.5-bound heavy metals might interact with profound cardiovascular alterations.

A follow-up study on the characterization and health risk assessment of heavy metals in ambient air particles emitted from a municipal waste incinerator in Zhejiang, China.

To confirm our hypothesis that inhalation might be the primary exposure route of heavy metals for children living in proximity to a municipal waste incinerator (MWI), we conducted a one-year follow up study to characterize the distributions of heavy metals featured in different types of ambient air particles, including PM1, PM2.5 and PM10, at two exposure sites near the MWI (E1 and E2) and one control site (C) in Zhejiang, China. Particle samples were collected by a mid-volume sampler and heavy metals were determined by the inductively coupled plasma mass spectrometry method. The mass concentrations of PM1, PM2.5 and PM10 were 52.0, 85.8 and 100.3 µg/m3 at E1 site, while the concentrations were 40.2, 92.1 and 106.6 µg/m3 at E2 site and 33.4, 55.6 and 66.1 µg/m3 at C site, respectively. Both E1 and E2 had higher PM1, PM2.5 and PM10 levels than C site. The levels of pollution were season dependent, with autumn having the highest levels of PM1, PM2.5 and PM10 across all three sampling sites. Regarding the distributions of heavy metals, Pb accounted for the majority of the seven metals in all groups, ranging from 43.2% to 51.3%, followed by Mn that ranged from 22.0% to 32.0%. The Pb levels of PM1, PM2.5 and PM10 in the MWI area were 22.6, 34.2 and 36.2 ng/m3, respectively, while Mn levels were 10.1, 20.0 and 23.5 ng/m3, respectively. The health risk assessment results suggested that residents were suffering high non-carcinogenic risk posed by MWI-emitted particle-bound toxic metals, as well as the high lifetime carcinogenic risk. This study revealed that ambient air, no matter whether near or far away from an MWI, bore more PM1, PM2.5 and PM10 particles than general, non-polluted ambient air, especially in autumn.

Characterization and health risk assessment of PM2.5-bound polycyclic aromatic hydrocarbons in 5 urban cities of Zhejiang Province, China.

In 2015, we measured polycyclic aromatic hydrocarbons (PAHs) in atmospheric fine particulate matter (PM2.5) collected from 5 cities in Zhejiang Province. The mean toxic equivalent quotient (TEQ) values of benzo(a)pyrene (BaP) ranged between 1.2-3.1 ng/m3. The BaP-TEQ displayed seasonal trends, such that winter > spring and autumn > summer. During the winter, the most abundant individual PAHs were 4-6ring PAHs (84.04-91.65%). The median daily intake of atmospheric PAHs ranged between 2.0-7.4 ng/day for all populations, with seasonal trends identical to that of BaP-TEQ. The 95th incremental lifetime cancer risk (ILCR) values induced by PM2.5-bound PAHs were far lower than 10-6 for all populations. The data suggested that the pollution levels in the 5 Zhejiang Province cities were higher than the Chinese National Ambient Air Quality Standard (NAAQS). In the future, relevant measures should be taken to control atmospheric PAHs, especially 4-6 ring PAHs. The data also revealed no obvious cancer risk for populations residing in these 5 cities of Zhejiang Province.

New Anode Material for Lithium-Ion Batteries: Aluminum Niobate (AlNb11O29).

This paper describes the syntheses and electrochemical properties of a new niobate compound, aluminum niobate (AlNb11O29), for Li+ storage. AlNb11O29-microsized particles and nanowires were synthesized based on the solid-state reaction and solvothermal methods, respectively. In situ X-ray diffraction results confirmed the intercalating mechanism of Li+ in AlNb11O29 and revealed its high structural stability against cycling. The AlNb11O29 nanowires with a novel bamboo-like morphology afforded a large interfacial area and short charge transport pathways, thus leading to the observed excellent electrochemical properties, including high reversible Li+-storage capacity (266 mA h g-1), safe operating potential (around 1.68 V), and high initial Coulombic efficiency (93.3%) at 0.1 C. At a very high rate (10 C), the AlNb11O29 nanowires still exhibited a capacity as high as 192 mA h g-1, indicating their good rate capability. In addition, at 10 C, 96.3% capacity was retained over 500 cycles, indicating superior cycling stability. A full cell fabricated with AlNb11O29 nanowires as the anode and LiNi0.5Mn1.5O4 microparticles as the cathode delivered a high energy density of 390 W h kg-1 at 0.1 C. This work suggests that the AlNb11O29 nanowires hold a great promise for the development of high-performance lithium-ion batteries for large-scale energy-storage applications.

Spatiotemporal Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 in Zhejiang Province.

The spatiotemporal characteristics and human health risks of 12 heavy metals (Al, As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sb, Se, and Tl) in fine particulate matter (PM2.5) in Zhejiang Province were investigated. The annual average PM2.5 concentration was 58.83 µg/m³ in 2015 in Zhejiang. Element contents in PM2.5 varied greatly with the season and locations. Al, Pb, and Mn were the most abundant elements among the studied metal(loid)s in PM2.5. The non-carcinogenic risks of the 12 elements through inhalation and dermal contact exposure were lower than the safe level for children and adults. However, there were potential non-carcinogenic risks of Tl, As, and Sb for children and Tl for adults through ingestion exposure. The carcinogenic risks from As, Be, Cd, Cr, Pb, and Ni through inhalation exposure were less than the acceptable level (1 × 10-4) for children and adults. Pb may carry a potential carcinogenic risk for both children and adults through ingestion. More attention should be paid to alleviate non-carcinogenic and carcinogenic health risks posed by particle-bound toxic elements through ingestion exposure.

Airborne particulate matter (PM2.5) triggers autophagy in human corneal epithelial cell line.

PURPOSE: To investigate particulate matter (PM2.5)-induced damage to human corneal epithelial cells (HCECs) and to determine the underlying mechanisms. METHODS: HCECs were exposed to PM2.5 at a series of concentrations for various periods. Cell viability was measured by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell proliferation was evaluated via 5-ethynyl-2'-deoxyuridine (EdU) analysis, while autophagy was determined by immunofluorescence and Western blot. RESULTS: PM2.5-induced cell damage of HCECs occurred in a time- and dose-dependent manner. Decreased cell viability and proliferation as well as increased apoptosis were observed in HCECs after PM2.5 exposure for 24 h. Autophagy in HCECs was slightly inhibited in the early stage (before 4 h) of exposure but significantly activated in the late stage (after 24 h), as evidenced by a decrease in the former and increase in the latter of the expression of the autophagy-associated markers LC3B, ATG5, and BECN1. Interestingly, rapamycin, an autophagy activator, attenuated early-stage but aggravated late-stage PM2.5-induced cell damage, suggesting that the role of autophagy in HCECs may change over time during PM2.5 exposure. In addition, in the early stage, the expression of LC3B and ATG5 increased in cells co-treated with rapamycin and PM2.5 compared to rapamycin-only or PM2.5-only treated cells, suggesting that autophagy may benefit cell viability after PM2.5 exposure. CONCLUSIONS: The results indicate the potential role of autophagy in the treatment of PM2.5-induced ocular corneal diseases and provide direct evidence for the cytotoxicity, possibly involving an autophagic process, of PM2.5 in HCECs.

[Effect factors of the prevalence of thyroid nodules in Zhejiang Province in 2010].

OBJECTIVE: To assess the prevalence of thyroid nodules and explore the risk factors for thyroid nodules among the community residents in Zhejiang Province. METHODS: The residents of twenty-two communities in Zhejiang Province were selectedwith stratified cluster sampling. The cross-sectional survey includes questionnaire, examination on thyroid. The prevalence and related factors of thyroid nodules was described, and the possible risk factors for thyroid nodules was analyzed with logistic regression. RESULTS: The prevalence of thyroid nodules in Zhejiang was 21. 78%, and the prevalence of a single nodule was 11. 75%, which was higher than that of multiple nodules( 10. 03%). The prevalence of thyroid nodules in men was less than women, urban residents higher than rural, and both increased gradually with age. The residents in coastal areas had the highest prevalence of thyroid nodules, followed by sub-coastal areas, inland minimum. High education level, consumption of seafood habits, high frequency of anger, the history of thyroid disease and iodine deficiency were potential risk factors for thyroid nodules in this surveyed population. CONCLUSION: The prevalence of thyroid nodules in Zhejiang Province was at the middle level, female prevalence was greater than male, and gradully increased with age, the elderly should be the focus of prevention. Although thyroid nodules of children was at the lower rate, it should be paid attention due to high risk to develop to malignancy. High education level, consumption of seafood habits, high frequency of anger, the history of thyroid disease and iodine deficiency were potential risk factors for thyroid nodules, which need to be confirmed by further epidemiologic study.

Application of the Benchmark Dose (BMD) Method to Identify Thresholds of Cadmium-Induced Renal Effects in Non-Polluted Areas in China.

The benchmark dose (BMD) method has been increasingly used to assess the health risks of cadmium (Cd) in epidemiological studies. The aim of our study was to estimate the threshold levels of urinary Cd (UCd) using the BMD method in a general population of Jiangshan City, Zhejiang Province of China. In our study, a total of 934 people (469 men, 465 women) were recruited and morning urine samples were collected from all the participants. Levels of Cd, creatinine, and renal dysfunction indicators such as retinol binding protein (RBP), ß2-microglobulin (ß2-MG), and N-acetyl-b-glucosaminidase (NAG) in urine were detected for analysis of BMD and BMD low (BMDL) of UCd. RBP, ß2-MG, and NAG in urine all correlated significantly (P < 0.001) with UCd except of age (P = 0.767). When the benchmark response (BMR) was 5%, the BMD/BMDL of UCd for RBP, ß2-MG, and NAG was 1.69/ 0.89, 1.24/0.62, 0.85/0.49 µg/g Cr in men and 1.70/0.76, 1.35/0.64, 1.36/0.65 µg/g Cr in women, respectively. If the BMR was set at 10%, the BMD/BMDL of UCd for RBP, ß2-MG, and NAG was 2.44/1.59, 2.09/1.30, 1.80/1.04 µg/g Cr in men and 2.43/1.53, 2.10/1.34, 2.31/1.37 µg/g Cr in women, respectively. Our results provided evidence for Cd-induced tubular effects in cadmium non-polluted areas in China. Both ß2-MG and NAG were more sensitive than RBP in response to Cd exposure. But ß2-MG was the most sensitive indicator in women, and NAG was the most sensitive one in men.

[Investigation of urinary cadmium characteristics of the general population in three non-cadmium-polluted rural areas in China].

OBJECTIVE: To investigate the characteristics of urinary cadmium of the non-occupational-cadmium-exposed population in non-cadmium contaminated rural area in China. METHODS: Randomly selected non-occupational cadmium exposed population 2548 people (male 1290, female 1258) with each gender and age groups, questionnaire surveyed and collected random urine. Urinary cadmium and urinary creatinine (Cr) concentration were tested, excluding urinary Cr < 0.3 g/L and > 3 g/L. Analyze the impact factors of urinary cadmium and calculated 95% quantile (P95) of urinary cadmium after correction by urinary Cr. RESULTS: Urinary cadmium increased with age and showed an upward trend. The urinary cadmium of the population of ≥ 30 years old was significantly higher than that of < 30 years old, women significantly higher than male, and smokers significantly higher than non-smokers (P < 0.01). Generalized linear model for multivariate analysis showed that smoking, age and gender are still significantly affected on urinary cadmium after adjusting for other factors (P < 0.01), regression equation: urinary cadmium (Cr corrected) = 0.854 + 0.325 x smoking + 0.111 x age--0.305 x gender (F = 367.69, P < 0.01). However, the multiple correlation coefficient of regression equation R2 = 0.0350, which is only 3.50% available in urinary cadmium variations can be explained by gender, age, and smoking. According to gender, smoking and < 30 and ≥ 30 years of age, analysis the upper limit of cadmium in urine, the 95% upper limit of urinary cadmium of ≥ 30 year-old female smokers (13.47 µg/g Cr) was significantly higher than other populations (< 6.0 µg/g Cr), the 95% upper limit of urinary cadmium of ≥ 30 year-old female and ≥ 30 year-old male smokers exceeded the urinary cadmium limits (5 µg/g Cr) of the occupational cadmium poisoning diagnostic criteria in China (GB Z17-2002). CONCLUSION: The urinary cadmium reference value of non-occupational-cadmium-exposed populations is < 6.0 µg/g Cr in the three non-cadmium contaminated rural area in China, but for smoking women over 30 year-old it needs more research to explore.

Immunoregulatory effects of ethyl-acetate fraction of extracts from Tetrastigma hemsleyanum Diels et. Gilg on immune functions of ICR mice.

OBJECTIVE: To evaluate the effects of ethyl-acetate fraction (EAF) of extracts from Tetrastigma hemsleyanum Diels et. Gilg (TDG) on immune functions of ICR mice. METHODS: ICR mice were exposed to different doses of EAF for 15 or 30 days and then their immune functions were analyzed, including ConA-induced splenic lymphocyte transformation, SRBC-induced delayed type hypersensitivity response, serum hemolysin analysis, antibody-producing cells, peritoneal macrophage phagocytized chicken red blood cells, natural killer cell activity, and serum level of cytokines. RESULTS: EAF of extracts from TDG at different doses had various effects on immune functions of ICR mice. As compared with the controls, it increased the mouse spleen lymphocyte transformation induced by ConA, the left-hind voix pedis thickness and the number of plague forming cells (PFCs) at the dose of 1.82 mg/mL, 5.48 mg/mL, and 9.12 mg/mL, respectively; increased the ink clearance ability at the dose of 0.91 mg/mL, 1.82 mg/mL, 5.48 mg/mL, and 9.12 mg/mL, respectively; increased the phagocytosis index of mononuclear-macrophages and production of serum interferon-gamma (IFN-gamma) at the dose of 5.48 mg/mL; and could promote the production of serum tumor necrosis factor-alpha (TNF-alpha) at the dose of 9.12 mg/mL. CONCLUSION: EAF of extracts from TDG can regulate mouse immune functions in vivo.

Expression of the human hepatitis B virus large surface antigen gene in transgenic tomato plants.

The original hepatitis B virus (HBV) large surface antigen gene was synthesized. In order to optimize the expression of this gene in tomato plants, the tobacco pathogenesis-related protein S signal peptide was fused to the 5' end of the modified gene and the sequence encoding amino acids S, E, K, D, E, and L was placed at the 3' end. The gene encoding the modified HBV large surface antigen under the control of a fruit-specific promoter was constructed and expressed in transgenic tomato plants. The expression of the antigen from transgenic plants was confirmed by PCR and reverse transcriptase PCR. Enzyme-linked immunoassays using a monoclonal antibody directed against human serum-derived HBsAg revealed that the maximal level of HBsAg was about 0.02% of the soluble protein in transgenic tomato fruit. The amount of HBsAg in mature fruits was found to be 65- to 171-fold larger than in small or medium fruits and leaf tissues. Examination of transgenic plant samples by transmission electron microscopy proved that HBsAg had been expressed and had accumulated. The HBsAg protein was capable of assembling into capsomers and virus-like particles. To our knowledge, this is the first time the HBV large surface antigen has been expressed in plants. This work suggests the possibility of producing a new alternative vaccine for human HBV.