Revealing the pathogenesis of gastric intestinal metaplasia based on the mucosoid air-liquid interface.

BACKGROUND: Gastric intestinal metaplasia (GIM) is an essential precancerous lesion. Although the reversal of GIM is challenging, it potentially brings a state-to-art strategy for gastric cancer therapeutics (GC). The lack of the appropriate in vitro model limits studies of GIM pathogenesis, which is the issue this work aims to address for further studies. METHOD: The air-liquid interface (ALI) model was adopted for the long-term culture of GIM cells in the present work. This study conducted Immunofluorescence (IF), quantitative real-time polymerase chain reaction (qRT-PCR), transcriptomic sequencing, and mucoproteomic sequencing (MS) techniques to identify the pathways for differential expressed genes (DEGs) enrichment among different groups, furthermore, to verify novel biomarkers of GIM cells. RESULT: Our study suggests that GIM-ALI model is analog to the innate GIM cells, which thus can be used for mucus collection and drug screening. We found genes MUC17, CDA, TRIM15, TBX3, FLVCR2, ONECUT2, ACY3, NMUR2, and MAL2 were highly expressed in GIM cells, while GLDN, SLC5A5, MAL, and MALAT1 showed down-regulated, which can be used as potential biomarkers for GIM cells. In parallel, these genes that highly expressed in GIM samples were mainly involved in cancer-related pathways, such as the MAPK signal pathway and oxidative phosphorylation signal pathway. CONCLUSION: The ALI model is validated for the first time for the in vitro study of GIM. GIM-ALI model is a novel in vitro model that can mimic the tissue micro-environment in GIM patients and further provide an avenue for studying the characteristics of GIM mucus. Our study identified new markers of GIM as well as pathways associated with GIM, which provides outstanding insight for exploring GIM pathogenesis and potentially other related conditions.

Safety and immunogenicity of quadrivalent meningococcal polysaccharide vaccine (MPV ACYW135) compared with quadrivalent meningococcal conjugate vaccine (Menactra®) in Malian children.

Affordable, polyvalent meningococcal vaccines are needed for use in emergency reactive immunization campaigns. A phase IV randomized, observer-blind, controlled study compared the safety and immunogenicity of a quadrivalent meningococcal polysaccharide vaccine (MPV-4, MPV ACYW135) and quadrivalent meningococcal ACWY conjugate vaccine (MCV-4, Menactra®). Healthy, 2- to 10-year-old children in Bamako, Mali, were randomized 1:1 to receive one dose of MPV-4 or MCV-4. Safety outcomes were evaluated for 6 months post-immunization. Immunogenicity for all serogroups was assessed for non-inferiority between MPV-4 and MCV-4 30 days post immunization by serum bactericidal antibody assay using baby rabbit complement (rSBA). From December 2020 to July 2021, 260 healthy subjects were consented and randomized. At Day 30 post-immunization, the proportions of subjects with rSBA titers ≥ 128 for all serogroups in the MPV-4 group were non-inferior to those in MCV-4 group. The proportions of subjects with rSBA ≥ 4-fold increase and rSBA titers ≥ 8 for all serogroups were similar among vaccine groups (P > .05). Geometric Mean Titers and Geometric Mean Fold Increases for all serogroups in both vaccine groups were similar (P > .05). Few local and systemic post-immunization reactions of similar severity and duration were observed within 7 days and were similar in both groups (P > .05). All resolved without sequelae. Unsolicited adverse events were similar in both groups regarding relationship to study vaccine, severity and duration. No serious adverse events were reported during the study period. MPV ACYW135 showed a non-inferior immunogenicity profile and a comparable reactogenicity profile to MCV-4 in Malian children aged 2-10 years.Clinical Trial Registration: NCT04450498.

Transfer of La, Ce, Sm and Yb to alfalfa and ryegrass from spiked soil and the role of Funneliformis mosseae.

Rare earth elements (REEs) are widely used in high-tech industries, and REE waste emissions have become a concern for ecosystems, food quality and human beings. Arbuscular mycorrhizal fungi (AMF) have repeatedly been reported to alleviate plant stress in metal-contaminated soils. To date, little information is available concerning the role of AMF in REE-contaminated soils. We recently showed that there was no transfer of Sm to alfalfa by Funneliformis mosseae, but only a single REE was examined, while light and heavy REEs are present in contaminated soils. To understand the role of AMF on the transfer of REEs to plants, we carried out an experiment using alfalfa (Medicago sativa) and ryegrass (Lolium perenne) in compartmented pots with separate bottom compartments that only were accessible by F. mosseae fungal hyphae. The bottom compartments contained a mixture of four REEs at equal concentrations (La, Ce, Sm and Yb). The concentration of REEs in plants was higher in roots than in shoots with higher REE soil-root than root-shoot transfer factors. Moreover, significantly higher light-REEs La and Ce were transferred to ryegrass shoots than Sm and the heavy-REE Yb, but this was not observed for alfalfa. Alfalfa dry weight was significantly increased by F. mosseae inoculation, but not ryegrass dry weight. For both plant species, there was significantly higher P uptake by the mycorrhizal plants than the nonmycorrhizal plants, but there was no significant transfer of La, Ce, Sm or Yb to alfalfa and ryegrass roots or shoots due to F. mosseae inoculation.

Stress, coping strategies and expectations among breast cancer survivors in China: a qualitative study.

BACKGROUND: Breast cancer is a common tumor in China and has become a public health problem in modern society. Stress plays an important role in the occurrence and progression of cancer. At present, the current situation of stress on breast cancer survivors (BCSs) in China has not been fully understood. This study aims to explore the stress and coping strategies of Chinese BCSs, which provide suggestions to help BCSs reduce stress. METHODS: Sixty-three BCSs from the Shanghai Cancer Rehabilitation Club in China were included in this study and were divided into eight focus groups. These were transcribed verbatim, coded using thematic analysis and analyzed using NVivo 11. RESULTS: Three themes were extracted from the data to address our research objectives: stress, coping strategies and expectations. The stress of BCSs included psychological stress, stress caused by physical pain, economic stress, stress caused by the change of life status, and stress caused by information overload; the coping strategies included self-strategies and help from others; from the perspective of the survivors, they put forward their expectations for both the society and themselves. CONCLUSIONS: This study shows that BCSs face a variety of stress. In the face of stress, BCSs need comprehensive support, including social and family support to cope with stressors. The findings from this study provide evidence for improving the quality of life among BCSs.

No significant transfer of the rare earth element samarium from spiked soil to alfalfa by Funneliformis mosseae.

Rare earth elements including samarium have been widely used in modern technologies in recent decades. Following over-exploitation and soil contamination, they can accumulate in plants and be toxic at high concentrations. Arbuscular mycorrhizae benefit plants in metal-contaminated soils by improving their survival and growth and alleviating metal toxicity, but little information is available about soil contaminated by rare earth elements. We performed two experiments using samarium to study the role of arbuscular mycorrhizal fungi on plant growth and samarium transfer to alfalfa in a samarium-spiked soil. A pot experiment was conducted in a soil spiked with two concentrations of samarium and a non-spiked control, inoculated or not with a metal-tolerant Funneliformis mosseae. A compartmented pot experiment was then performed with a separated compartment containing samarium-spiked sand only accessible by F. mosseae fungal hyphae to further study the transport of samarium from the soil to alfalfa. The biomass of alfalfa grown on samarium-spiked soil was reduced, while it was significantly higher following arbuscular mycorrhiza inoculation in the pot experiment, both in the control and samarium-spiked soil. Although mycorrhizal plants had a higher phosphorus content than non-mycorrhizal ones, there was no significant difference in samarium concentrations between mycorrhizal and non-mycorrhizal plants. The compartment experiment confirmed that there was no significant samarium transfer to the plant by F. mosseae. Other fungi and plants should be tested, and field experiments performed, but our results suggest that arbuscular mycorrhizal plants might be considered in phytorestoration of rare-earth-contaminated soils.

Bioavailability and transfer of elevated Sm concentration to alfalfa in spiked soils.

Rare earth elements (REEs) have been widely used in recent decades, and their exploitation has led to industrial REE emission and to contaminated soils especially in former mining areas. This raised people concerns on the accumulation and toxicity of REEs in soils and plants, and consequences on plant health. Although many studies dealt with REE in soils and plants, there is still a need to precise their toxicity, bioavailability and transfer to plants in contaminated sites in order to restore such ecosystems. We studied the bioavailability and transfer of a REE to Medicago sativa grown on two contaminated soils differing in their chemical characteristics. A pot experiment was set up in a growth chamber where two natural soils were spiked or not with samarium (Sm) as a model REE. Two chemical extractants were tested to estimate the bioavailability of Sm in the soil, its decrease with time and its transfer to the plants. Results showed that DTPA extractable Sm was well correlated with Sm uptake in alfalfa shoots. The experiment pointed out a significant ageing effect since DTPA extractable Sm significantly decreased within 2 weeks in the soils and was significantly lower in the less acidic soil than in the other. The uptake of Sm from soil to alfalfa shoots depended on the soil pH and on the spiking concentration. The soil to plant transfer factor was low (< 0.08), but a 30% reduction of alfalfa biomass was observed when the soils were spiked with 100 to 200 mg kg-1 of Sm.

Three-dimensional culture of MSCs produces exosomes with improved yield and enhanced therapeutic efficacy for cisplatin-induced acute kidney injury.

BACKGROUND: Exosomes derived from mesenchymal stem cells (MSC-exos) have been demonstrated with great potential in the treatment of multiple human diseases including acute kidney injury (AKI) by virtue of their intrinsic cargoes. However, there are major challenges of low yield and the lack of an established biomanufacturing platform to efficiently produce MSC-exos, thereby limiting their therapeutic application. Here, we aimed to establish a novel strategy to produce MSC-exos with a hollow fiber bioreactor-based three-dimensional (3D) culture system and evaluate the therapeutic efficacy of 3D-exosomes (3D-exos) on AKI. METHODS: Mesenchymal stem cells (MSCs) were isolated from fresh human umbilical cord and cultured in two-dimensional (2D) flasks. 2 × 108 MSCs were inoculated into the hollow fiber bioreactor for 3D culture. The culture supernatants were collected every 1 or 2 days for isolating exosomes. Exosomes from 2D (2D-exos) and 3D cultures were characterized by transmission electron microscopy, nanoparticle tracking analysis, and western blotting analysis of exosome markers. The yield of exosomes from 2 × 108 MSCs seeded in 2D and 3D culture system was compared, based on protein quantification. The therapeutic efficacy of 2D-exos and 3D-exos was investigated in a murine model of cisplatin-induced AKI in vivo and in vitro. RESULTS: 3D culture did not significantly change the surface markers of MSCs, as well as the morphology, size, and exosomal markers of 3D-exos when compared to those of 2D-exos. Compared with conventional 2D culture, the 3D culture system increased total exosome production up to 19.4-fold. 3D-exos were more concentrated in the harvested supernatants (15.5-fold) than 2D-exos, which led to a higher exosome collection efficiency of 3D culture system. In vivo, both 2D-exos and 3D-exos significantly alleviated cisplatin-induced murine AKI evidenced by improved renal function, attenuated pathological changes of renal tubules, reduced inflammatory factors, and repressed T cell and macrophage infiltration. Impressively, 3D-exos were more effective than 2D-exos. Moreover, 3D-exos were taken up by tubular epithelial cells (TECs) with improved efficiency, thereby exhibiting superior anti-inflammatory effect and improved viability of TECs in vitro. CONCLUSIONS: In summary, our findings demonstrate that the hollow fiber 3D culture system provides an efficient strategy for the continuous production of MSC-exos which has enhanced therapeutic potential for cisplatin-induced AKI.

Distribution, Sources, and Health Risk Assessment of Volatile Organic Compounds in Hefei City.

Volatile organic compounds (VOCs) are involved in the formation of ozone formation, which plays a significant role in regional air contamination and poses a great threat to human health. The VOCs were collected from the urban area of Hefei city via an off-line sampling method (SUMMA canister) and determined by gas chromatography-mass spectrometer. The average concentrations of VOCs were 17.65 ± 28.36 ppbv, which were mainly contributed by aromatics (10.02 ± 13.37 ppbv), haloalkane (5.37 ± 8.90 ppbv), ally halide (1.25 ± 3.36 ppbv), and aryl halid (1.02 ± 2.73 ppbv). According to the principal component analysis, three major sources were identified, including solvent use, vehicle exhaust, and industrial release, accounting for 70.6% of the total variance of the data. Health risk assessment was utilized to evaluate the potential adverse health effects of the individual VOC. The total hazard ratio in the selected area was higher than 1, where could pose health threat to exposed population. The cancer risk for benzene, carbon tetrachloride, trichloromethane, and 1, 2-dichloroethane were 4.8 × 10-5, 4.5 × 10-5, 3.3 × 10-5, and 2.5 × 10-5, respectively, indicating definite health risks.

Source identification of heavy metals and stable carbon isotope in indoor dust from different functional areas in Hefei, China.

Dust on air conditioning filters can represent the re-suspended particulate matter in indoor air, which may pose potential health risks to humans. However, source identification and influence factors of indoor dust are controversial. The present study investigated the distribution of Cd, Cr, Mn, Ni, Pb, Sb, V, and Zn, as well as stable carbon isotope, in indoor dust from three different functional zones in Hefei to discuss the sources and influence factors of indoor dust. PCA analysis of heavy metals showed that indoor sources (such as cooking and smoking) were the main sources. Negative correlation appeared between family size and heavy metal concentrations. This was because people acted as a sink of pollutants. Concentration analysis of heavy metals revealed that smoking and cooking had weak relevance with heavy metal concentrations. While through the δ13C analysis, cooking had a significant correlation with δ13C of indoor dust, instructing that cooking was a significant source of indoor dust. Besides, smoking also had a certain correlation with δ13C of indoor dust, instructing that smoking was one of the sources of indoor dust.

Characteristics and health risk assessment of heavy metals in indoor dust from different functional areas in Hefei, China.

Metals in indoor dust pose potential health risks to humans. Dust deposition on air conditioner filters can represent the resuspended particulate matter in indoor air. However, few studies have examined this until now. This study investigated the total concentrations and different chemical fractionations of Cd, Cr, Mn, Ni, Pb, Sb, V, and Zn in indoor dust from three different functional zones (the Chief District, Commercial District (CmD), and Industrial District) in Hefei. The mean metal concentrations in indoor dust decreased in the following order: Zn > Mn > Pb > Cr > Ni > V > Cd > Sb. Cd, Pb, and Zn mainly existed in the mobile fraction. Cr and V mainly existed in the residual fraction. The enrichment factor and geo-accumulation index values of heavy metals were all ranked in the order of Cd > Zn > Pb > Sb > Ni > Cr > V, and these values in indoor dust were larger than those in outdoor dust. In addition, the enrichment patterns of these elements were similar in the three functional areas. The orders of non-carcinogenic risk (hazard index; HI) for the different functional areas for children were roughly the same, but there were clear differences for adults. In general, all the HIs were less than 1, which were within the internationally recognized safe range. The total carcinogenic risk (TR) was in the order of Cr > Pb > Cd for both children and adults in the three functional zones. The TRs from Cr exposure were not negligible. The TRs were significantly higher in the CmD.

Similarities and differences in PM10 and PM2.5 concentrations, chemical compositions and sources in Hefei City, China.

Atmospheric particulates were sampled in Hefei City, China from October 2016 to January 2017 to compare chemical compositions and sources of PM2.5 (particle size smaller than 2.5 µm) and PM10 (particle size smaller than 10 µm). The mean levels of PM2.5 and PM10 were 81 and 109 µg/m3, which are higher than the health threshold levels regulated by national and international standards. During the sampling period, AQI (Air Quality Index) was strongly correlated with PM2.5 (Pearson's coefficient r = 0.94) rather than PM10 concentrations. The PM2.5/PM10 ratios were approximately 0.7, revealing the characteristics of fine particle pollution. Pollution elements (S, Zn, Cu and Pb) took up a large proportion of the composition and had high enrichment factors of 437, 385, 20 and 53, respectively, in PM10. Coal combustion and high-tech manufacture industry discharges were suggested to be the main pollution sources of both PM2.5 and PM10. The PM2.5/PM10 ratios of anthropogenic element concentrations were much higher than ratios of earth crust element. As compared to PM10, S and Pb in PM2.5 had larger EFs, indicating that pollution elements were predominantly enriched in PM2.5. Furthermore, a paired sample t-test confirmed similar sources of PM2.5 and PM10. Our study provides basic database to evaluate the heavy metal pollution status of atmospheric particulates in Chinese cities.

Platinum in sediments and mussels from the northwestern Mediterranean coast: Temporal and spatial aspects.

Platinum (Pt) is considered a Technology Critical Element (TCE) and an emerging metallic contaminant with increasing release into the environment. Gaps in knowledge and understanding of environmental levels, fate and effects of Pt still exist, especially in the marine environment. This work presents Pt concentrations in the northwestern Mediterranean coast including: (i) temporal variability from sediment cores and farmed mussels in the Toulon Bay (historically affected by intense human activities) and (ii) spatial distribution from recent wild mussels collected along ∼ 700 km coastline with contrasting ecosystems (including natural reserves), quantified using voltammetry and inductively coupled plasma-mass spectrometry. The historical (>100 years) record of Pt in sediments from the Toulon Bay suggests the existence of non-negligible Pt sources older than those related to vehicle emission devices, such as petrol industry and coal-fired activities. A strong Pt increase in more recent sediments (from ∼12 to 16 ng g-1) and mussels (8-fold increase from ∼0.12 to 0.80 ng g-1) covering the past 25 years reflect the overall evolution of Pt demand in Europe (∼20-fold increase for vehicle catalysts in 20 years). Spatial biomonitoring of Pt in mussels along the northwestern Mediterranean coast is assumed to reflect inter-site differences of Pt exposure (0.09-0.66 ng g-1) despite seasonal effect on tissue development. This study highlights the need for thorough and regular monitoring of Pt levels in sediments and biota from urbanized coastal areas in order to better assess the environmental impact of this TCE, including potential risks for marine organisms.

Activated protein C inhibits lung injury induced by LPS via downregulating MAPK signaling.

The aim of the present study was to investigate the effect and the underlying mechanism of activated protein C (APC) in lipopolysaccharide (LPS) induced lung injury, as well as the potential mechanism. According to the treatment, 50 rats were randomly divided into 5 groups: Control, model (LPS), low-dose group [LPS + 0.1 mg/kg recombined human activated protein C (rhAPC)], median-dose group (LPS + 0.3 mg/kg rhAPC) and high-dose group (LPS + 0.5 mg/kg rhAPC). Then, inflammation in the lung was assessed using hematoxylin and eosin (H&E) staining. Following the collection of bronchoalveolar lavage fluid (BALF), the number of leukocytes and neutrophils in BALF was counted, and superoxide dismutase (SOD) activity was assessed, as well as the expression levels of interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α using ELISA. Subsequently, the expression and phosphorylation of P-38, extracellular signal-regulated kinase (Erk)-1/2, and c-Jun N-terminal kinase (JNK) were estimated using western blotting. Based on H&E staining, rhAPC markedly suppressed inflammatory infiltration in the lung induced by LPS in a dose-dependent manner. In addition, rhAPC also significantly attenuated the accumulation of leptocytes and neutrophils, and the reduction of SOD in BALF induced by LPS in a dose-dependent manner. rhAPC also significantly attenuated the elevation of IL-1ß, IL-6 and TNF-α in BALF induced by LPS in a dose-dependent manner. Further mechanistic analysis revealed that rhAPC treatment could evidently attenuate the phosphorylation levels of P-38, Erk1/2 and JNK in the lung induced by LPS in a dose-dependent manner. In conclusion, APC significantly alleviated the lung inflammation induced by LPS by downregulating the phosphorylation of P-38, ERK1/2 and JNK.

Levels, characteristics and health risk assessment of VOCs in different functional zones of Hefei.

In order to study the characteristics and health risk of VOCs in the ambient air in the typical developing cities in China, the research was conducted in five functional zones in Hefei from September 2016 to January 2017. The average concentrations of total measured VOCs in traffic zone was the largest (85.94 µg m-3), followed by industrial zone (64.84 µg m-3), development zone (58.92 µg m-3), resident zone (57.31 µg m-3), and background zone (54.94 µg m-3). Cl-VOCs were most abundant species in chlorinated VOCs (85.06%), which showed much higher level in industrial zone. the mean value of BTEX found in presented study was 65.19 µg m-3. Based on the specific VOC ratio method (B/T), the observed sites were greatly affected by the traffic emissions. The ratios of T/B, E/B and X/B were 1.15, 1.35 and 0.47, respectively, possibly due to the aging air mass. Carcinogenic risks for benzene, carbon tetrachloride, trichloroethylene, 1, 2-dichloroethane and chloroform were higher than the general acceptable risk level of 1.00 × 10-6. Potential non-carcinogenic risk assessment showed that hazard quotient (HQ) of 10 VOCs not exceeded unity, but the hazard risk index (HI) at site ED, LY, YH and HD were both higher than 1.

Characteristic and Source of Atmospheric PM10- and PM2.5-bound PAHs in a Typical Metallurgic City Near Yangtze River in China.

The characteristics of atmospheric PM10- and PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) were investigated in Tongling city, China. Results showed that the total concentrations of PM10- and PM2.5-bound PAHs exhibited distinct seasonal and spatial variability. The metallurgic sites showed the highest PAH concentrations, which is mainly attributed to the metallurgic activities (mainly copper ore smelting) and coal combustion as the smelting fuel. The rural area showed the lowest concentrations, but exhibited significant increase from summer to autumn. This seasonal fluctuation is mainly caused by the biomass burning at the sites in the harvest season. The diagnostic ratio indicated that the main PAHs sources were vehicle exhausts, coal combustion and biomass burning. The total BaP equivalent concentration (BAP-TEQ) was found to be maximum at DGS site in winter, whereas it was minimum at BGC site in summer. Risk assessment indicates that residential exposure to PAHs in the industrial area, especially in the winter season, may pose a greater inhalation cancer risk than people living in living area and rural area.

Particle-Associated Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Hefei, China: Levels, Characterizations and Health Risks.

Airborne PM2.5 and PM10 samples were collected in summertime (August 2015) and wintertime (December 2015-January 2016) in an industrial complex area in Hefei, China. The average concentrations of PM2.5 and PM10 (90.5 and 114.5 µg/m3, respectively) were higher than the regulated levels of China National Ambient Air Quality Standard (grade I) and the WHO Ambient (outdoor) Air Quality and Health Guideline Value. Seasonal variations in PM2.5/PM10 indicated that the secondary sources of particulate matters, formed by gas-to-particle conversion, were enhanced in summer due to longer time of solar radiation and higher temperature. The total concentrations of PM2.5- and PM10-associated PAHs were 5.89 and 17.70 ng/m3 in summer as well as 63.41 and 78.26 ng/m3 in winter, respectively. Both PM2.5- and PM10-associated PAHs were dominated by 4- to 6-ring PAHs, suggesting that the fossil fuel combustion and vehicle emissions were the primary sources of PAHs in atmospheric particulate matters in Hefei. The total concentration of PAHs had a slightly higher correlation coefficient with PM2.5 (R = 0.499, P < 0.05) than PM10 (R = 0.431, P > 0.05), indicating the higher association tendency of PAHs with PM2.5. The coefficient of divergence analysis showed that the compositions of PAH were quite different between summer and winter. Total BaP equivalent concentration (BaP-TEQ) for particulate-bound PAHs in winter (58.87 ng/m3) was higher than that in summer (5.53 ng/m3). In addition, particulate-bound PAHs in winter had an inhalation cancer risk (ICR) value of 2.8 × 10-3, which was higher than the safe range (10-4-10-6).

Tracing platinum accumulation kinetics in oyster Crassostrea gigas, a sentinel species in coastal marine environments.

Platinum Group Elements (PGEs) are extremely scarce in the Earth's Crust and of strong interest for high-end technologies due to their specific properties. They belong to the Technology Critical Elements (TCEs) for which use is forecast to increase, implying growing emissions into the environment in the following years. In particular, with the intensive use of platinum (Pt) in car catalytic converters, the anthropogenic geochemical cycle of this element has surpassed the natural cycle. Yet, environmental Pt levels are still in the sub picomolar range, making its analytical detection a challenge. Few studies cover the behavior of Pt in marine waters in terms of speciation, reactivity and possible transfer to the biota. In this study, oysters (Crassostrea gigas) from an unpolluted estuary were exposed to the stable isotope 194Pt in seawater at a range of concentrations during 35days. Seawater was renewed daily and spiked to three nominal Pt concentrations (50, 100, and 10,000ng·L-1) for two replicate series. In addition, control conditions were monitored. Five oysters from each tank were dissected after 3, 7, 14, 21, 28, 35days of Pt exposure, and analyzed by ICP-MS. Accuracy of this analytical method applied to biological matrix was checked by an inter-method comparison with a voltammetrical technique. A concentration-dependent accumulation of Pt in oysters increasing with exposure time occurred. After 28days, oyster Pt accumulation from low and intermediate exposure conditions reached a plateau. This was not the case of the highest exposure condition for which oyster tissues showed increasing concentrations until the last day of the experiment. A linear correlation exists between seawater concentrations and Pt content in oysters for low and intermediate exposure concentrations i.e. closer to environmental concentrations. By showing high Pt accumulation potential, oysters may serve as sentinels, ensuring biomonitoring of Pt concentrations in marine coastal waters.

Levels and Sources of PAHs in Air-borne PM2.5 of Hefei City, China.

This work studied the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in air-borne particulate matter of Hefei, China. Samples of PM2.5 were collected daily at two sites during May, 2014, and January, 2015. The average daily concentration of PM2.5 was 96.88 µg m-3, which is higher than the 2012 China Ambient Air Quality Standard (GB3095-2012 24-h grade II) of 75 µg m-3. The concentrations of 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography-mass spectrometry. The PM2.5-bound PAH concentrations ranged from 4.92 to 71.00 ng m-3 (mean = 21.34 ng m-3), and exhibited obvious seasonal (31.38 ng m-3 in winter and 14.05 ng m-3 in summer) and spatial variability (27.23 ng m-3at site ME and 18.20 ng m-3 at site MS). Meteorological conditions such as ambient temperature, wind speed and humidity had influences on the concentrations of PAHs. As an index for PAH carcinogenicity, the annual average concentration of benzo(a)pyrene ranged from 0.46 to 2.31 ng m-3, with a mean of 1.15 ng m-3. This mean was lower than the China Ambient Air Quality Standard (GB3095-2012) of 2.5 ng m-3. The diagnostic PAH ratios and principal component analysis (PCA) suggested that combustion of coal and vehicle emissions were the main sources of PAHs in PM2.5.

Culture and Identification of Bone Marrow Mesenchymal Stem Cells from Enhanced Green Fluorescent Protein-transgenic Rats.

OBJECTIVE: To isolate, culture, and identify bone marrow mesenchymal stem cells (BMSCs) from enhanced green fluorescent protein (EGFP)-transgenic rats in vitro. METHODS: Bone marrows were isolated from tibia and femur of healthy EGFP-transgenic rats of specific pathogen free (SPF) grade. Then,the whole bone marrow adherent method was used for isolation,culture,and purification of BMSCs. The morphological change was noted by continuous observation under inverted fluorescence microscope. The growth curve of cells was drawn through the method of CCK-8 and the proliferation compared with wild type BMSCs. The surface markers of BMSCs were detected by flow cytometry. The BMSCs were induced to differentiate into osteoblasts, adipocytes, and chondrocytes lineages. The EGFP-BMSCs were transplanted into the rats intravenously, and the expression of GFP was detected. RESULTS: BMSCs stably expressing EGFP gene were obtained successfully, with the fusiform-shaped appearance and the forming of circinate cell colonies. The growth curve of EGFP-MSCs showed the characteristic of active proliferation, showing no significant difference compared with the wild-type BMSCs. The expression rates of the surface markers of BMSCs CD29, CD90, CD34, CD49d, and CD45 were 99.4%, 96.4%, 0.171%, 0.049%, and 0.038%. The GFP were detected in lung 3 days after transplantation. After osteogenic, adipogenic, and chondrogenic induction, oil red-O and alizarin red positive signals and toluidine blue positive cells were detected. CONCLUSIONS: High-purity BMSCs stably expressing green fluorescent protein gene can be cultured using the whole bone marrow adherent method. EGFP does not affect the stem cell properties and expresses stably after transplantation. The cells can be used as seed cells for subsequent research.

Erythropoietin promotes the protective properties of transplanted endothelial progenitor cells against acute lung injury via PI3K/Akt pathway.

INTRODUCTION: Accumulating evidences have indicted the participation and repairing effects of endothelial progenitor cells (EPCs) on acute lung injury (ALI). Researchers have also revealed that erythropoietin (EPO) may exert multiple effects on EPCs including proliferative and adhesive properties. The present study was designed to investigate whether EPO can promote the healing efficiency of transplanted EPCs against ALI and the potential mechanism. METHODS: Endothelial progenitor cells were derived from bone marrow mononuclear cells of BALB/c mice. In our in vitro studies, we tested the proproliferative and antiapoptotic effects of EPO on cultured EPCs. In our in vivo studies, we induced BALB/c mice ALI model by intratracheal instillation of lipopolysaccharide and treated with/without intravenous injection of enhanced green fluorescent protein-EPCs harvested from enhanced green fluorescent protein-BALB/c mice. Mice that received EPC transplantation either underwent EPO administration or not. The effects of EPO and EPC treatment on promoting pulmonary endothelial repair, decreasing pulmonary capillary permeability, alleviating pulmonary inflammation, improving gas exchange, and promoting pulmonary vessel angiogenesis were tested. The potential mechanisms that mediate EPO functions on EPC were also investigated. RESULTS: Our studies revealed a significant antiapoptotic property of EPO on cultured EPCs as well as its promotion on EPC proliferation. We also found the severity of ALI was reduced by EPC therapy, and the protective effects of EPCs were highly enhanced when combined with EPO administration. However, all these stimulating effects of EPO on EPCs were consisted with the expression of phospho-Akt and were abrogated by PI3K inhibitors. CONCLUSIONS: Transplanted EPCs directly incorporated into the injured pulmonary vessels and maintain the integrity of pulmonary endothelium. Erythropoietin improved the survival and proliferation of transplanted EPCs and recruited them to the injured sites to exert their repairing functions. PI3K/Akt pathway mediated EPO's functions on EPCs. The combination of EPO and EPC treatment may be a promising cell-based therapy for ALI patients.