Reduced myocardial strain of interventricular septum among male amateur marathon runners: a cardiac magnetic resonance study.

OBJECTIVES: To analyze the long-term effect of multiple marathons on cardiac structure and function in amateur marathon runners compared with healthy controls. DESIGN: Cross-sectional study using male amateur marathon runners (n = 32) and age-matched cohort of male healthy controls (n = 12). METHODS: A total of 32 male amateur marathon runners (age 44 ±â€¯7 years) and 12 male healthy controls (age 42 ±â€¯8 years) underwent cardiac magnetic resonance (CMR). The relevant parameters of cardiac structure and function were studied employing feature-tracking strain analysis. RESULTS: Amateur marathon runners showed lower heart rates, body mass index and body surface area. The left ventricular (LV) mass index, LV end-diastolic volume index and right ventricular end-systolic volume index were significantly higher in amateur marathon runners compared with healthy controls. Furthermore, walls of interventricular septum (IVS) in amateur marathon runners were thicker than healthy controls. There was no significant difference between two groups in the global myocardial strain (MS) in LV. However, the segmental radial and circumferential strains of the LV were lower in amateur marathon runners compared to healthy controls, specifically in the 8th and 9th segments. Finally, we also found as the total running intensity increased, so did global longitudinal strain. CONCLUSIONS: We reported higher wall thickness and lower regional radial and circumferential strain in the IVS region in amateur marathon runners, suggesting that prolonged and high-intensity exercise may cause cardiac remodeling. Further studies are needed to investigate whether this is an adaptive or maladaptive change in amateur marathon runners.

Hippocampal Subfield Volumes in Amateur Marathon Runners.

PURPOSE: Numerous studies have implicated the involvement of structure and function of the hippocampus in physical exercise, and the larger hippocampal volume is one of the relevant benefits reported in exercise. It remains to be determined how the different subfields of hippocampus respond to physical exercise. METHODS: A 3D T1-weighted magnetic resonance imaging was acquired in 73 amateur marathon runners (AMR) and 52 healthy controls (HC) matched with age, sex, and education. The Montreal Cognitive Assessment, the Pittsburgh Sleep Quality Index (PSQI), and the Fatigue Severity Scale were assessed in all participants. We obtained hippocampal subfield volumes using FreeSurfer 6.0. We compared the volumes of the hippocampal subfield between the two groups and ascertained correlation between the significant subfield metrics and the significant behavioral measure in AMR group. RESULTS: The AMR had significantly better sleep than HC, manifested as with lower score of PSQI. Sleep duration in AMR and HC was not significantly different from each other. In the AMR group, the left and right hippocampus, cornu ammonis 1 (CA1), CA4, granule cell and molecular layers of the dentate gyrus, molecular layer, left CA2-3, and left hippocampal-amygdaloid transition area volumes were significantly larger compared with those in the HC group. In AMR group, the correlations between the PSQI and the hippocampal subfield volumes were not significant. No correlations were found between hippocampal subfield volumes and sleep duration in AMR group. CONCLUSIONS: We reported larger volumes of specific hippocampal subfields in AMR, which may provide a hippocampal volumetric reserve that protects against age-related hippocampal deterioration. These findings should be further investigated in longitudinal studies.

Multifunctional nanoparticle PEG­Ce6­Gd for MRI­guided photodynamic therapy.

Gliomas are one of the most common types of primary brain tumors. Despite recent advances in the combination of surgery, radiotherapy, systemic therapy (chemotherapy, targeted therapy) and supportive therapy in the multimodal treatment of gliomas, the overall prognosis remains poor and the long­term survival rate is low. Thus, it is crucial to develop a novel glioma management method. Due to its relatively non­invasive, selective and repeatable characteristics, photodynamic therapy (PDT) has been investigated for glioma therapy in the past decade, exhibiting higher selectivity and lower side effects compared with those of conventional therapy. However, most of the photosensitizers (PSs) are highly hydrophobic, leading to poor water solubility, rapid degradation with clearance in blood circulation and ultimately, low bioavailability. In the present study, hydrophilic polyethylene glycol (PEG)­chlorin e6 (Ce6) chelated gadolinium ion (Gd3+) nanoparticles (PEG­Ce6­Gd NPs) were synthesized via a chelation and self­assembly process. Initially, the cell cytotoxicity of PEG­Ce6­Gd NPs was evaluated with or without laser irradiation. The in vitro study demonstrated the lack of toxicity of PEG­Ce6­Gd NPs to tumor cells in the absence of laser irradiation. However, its toxicity was enhanced under laser irradiation. Moreover, the size and weight of brain tumors were significantly decreased in mice with glioma xenografts, which was further confirmed via histological analysis. Subsequently, the results indicated that the PEG­Ce6­Gd NPs had a favorable T1­weighted contrast performance (0.43 mg ml­1 s­1) and were observed to have significant contrast enhancement at the tumor site from 0.25 to 1 h post­injection in vivo. The favorable MRI, as well as the synergetic photodynamic antitumor effect and antineoplastic ability of PEG­Ce6­Gd NPs was identified. It was suggested that PEG­Ce6­Gd NPs had great potential in the diagnosis and PDT treatment of gliomas, and possibly other cancer types, with prospects of clinical application in the near future.

[Effects of Different Land Use Typess on the Molecular Ecological Network of Soil Bacteria].

The bacterial community composition in four land-use types was determined and the visualized bacterial network was constructed by 16S rDNA Illumina MiSeq high-throughput sequencing technology and a molecular ecological network method. The results show that Proteobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, Actinobacteria, Planctomycetes, Verrucomicrobia, Cyanobacteria, Gemmatimonadetes, Firmicutes, Nitrospirae, and Chlorobi are the main bacteria in this area. The number of nodes of urban green land, paddy field, and dry field bacteria networks is higher, and that of natural forest land is lower. The number of connections and average connectivity of dry fields are the highest; following are those of urban green land and paddy field, and those of natural forest land are the lowest. The four bacterial networks are dominated by positive correlation, and the ratio of competition relationship is TL > LD > HT > ST. The average network path and modularity of the soil bacteria networks of paddy field and dry land are small, while the average connectivity and clustering coefficient are higher. Some flora of Acidobacteria, Firmicutes, and Proteobacteria play an important role in the soil bacterial network in this area. The classification of operational taxonomic units is different among the key nodes of different bacterial molecular ecological networks, and there is almost no overlap. The relative abundance of bacteria of some key nodes in the four bacterial networks is low (<1%), and these are not the main bacteria in this area. The soil microflora in dry land are mainly affected by TP (P<0.05), the soil microflora in paddy field were mainly affected by clay, silt, and water content (P<0.05), and that in natural forest land and urban green land were mainly affected by C/N (P<0.05). The above results show that different land-use patterns lead to changes in soil physical and chemical properties and the interaction between soil bacteria species. The bacterial network of dry land soil is larger and the relationship between species is more complex. The bacteria in different land-use types are mainly cooperative, and the competition is weak. Compared with other land-use types, there is stronger competition between the bacteria in natural forest soil. The soil bacteria in paddy field and dry land are the most sensitive to the external environment, respond more quickly, and the community structure is easier to change. The response of soil bacteria in natural forest land and urban green land is slower, and the disturbance of environmental factors does not affect the whole bacterial ecological network in a short time, and thus the community structure is more stable. Some bacteria have the phenomenon of species role transformation between networks. The abundance and community distribution of microorganisms cannot indicate the strength of their connectivity between network nodes; low-abundance bacteria in soil play an important role in the construction of bacterial networks.

Evaluation of methotrexate-conjugated gadolinium(III) for cancer diagnosis and treatment.

BACKGROUND: Gliomas are one of the most common types of primary brain tumors. It is usually evaluated by gadolinium(III)-based contrast agents by magnetic resonance imaging (MRI) in the clinic. Methotrexate (MTX), as a type of folate analog that inhibits the enzyme dihydrofolate reductase, is widely used as a chemotherapeutic agent to treat gliomas in the experiment. PURPOSE: In this study, a novel theranostic agent MTX-DOTA-Gd (MTX-Gd) was synthesized, which integrates magnetic resonance imaging (MRI) with anticancer treatment. METHODS: MTX-Gd was synthesized by connecting MTX and Gd through 1,4,7,10-tetraazacy-clododecane-1,4,7,10-tetraacetic acid (DOTA). The characterization of MTX-Gd was detected by ultraviolet (UV) and infrared spectroscopy (IR). To confirm the antitumor effect of MTX-Gd, the cytotoxicity of MTX-Gd was examined by the MTT assay. The contrast enhancement of the MTX-Gd was measured through MRI in vitro. Then, nude mice bearing C6 tumor xenografts were used to study in vivo imaging capabilities. RESULTS: The ultraviolet-visible-near infrared radiation (UV-NIR) absorption curve indicated that MTX-Gd had a broad absorption in the region of 500-700 nm. The formation of MTX-Gd was confirmed from the characteristic bands of MTX-DOTA-Gd in the 1413 cm-1 (C-N), 1577 cm-1 (-NH2), and 3429 cm-1 (N-H), in the fourier-transform infrared (FTIR) spectra. MTX-Gd showed little difference in the cell viability compared with MTX, except for the highest concentration (270 µM). In vitro, the imaging of MTX-Gd was significantly brighter than Gd-DOTA at the same concentration, and the brightness and signal intensity of MRI were increased followed by the increased concentration of MTX-Gd. And it also showed that MTX was not visualized on MRI. The other images revealed that the concentration of 4 mM MTX-Gd had the same imaging effect with the concentration of 10 mM Gd-DOTA. Then, MTX-Gd was injected in nude mice bearing C6 tumor xenografts through the tail vein. Significant contrast enhancement was observed at the tumor site from 0.5 h to 3 h. The signal of tumor area was strongest at 3 h due to accumulation by size effect of macromolecules. CONCLUSION: A novel stable and unique theranostic agent (MTX-Gd) was successfully synthe-sized, and it has good stability, strong anticancer ability and excellent magnetic capacity. The methotrexate component of MTX-Gd, as a chemotherapeutic agent, played an important role in targeted therapies of cancer. The DOTA-Gd component of MTX-Gd performed as the MRI contrast agent. The superior MRI imaging performance and synergetic chemical antineoplastic ability of MTX-Gd was revealed, and it has great potential in the diagnosis and treatment of glioma and potentially other cancers, with prospects of clinical application in the near future.

[Pollution Characteristics and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Soils of Shenyang North New Area].

Topsoil (0-20 cm) samples (n=101) in 5 different land use types in Shenyang North New Area (SNNA), Shenyang, China were collected using the uniform grid layout method to investigate the spatial distribution characteristics, composition spectrum, and source analysis of 16 polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by the Environmental Protection Agency of the United States. Results showed that the total concentration of the 16 PAHs (ΣPAHs) in soils of SNNA ranged from 123.7 µg·kg-1 to 932.5 µg·kg-1. The PAH components were mainly dominated by 3-ring and 4-ring PAHs, of which the proportion of 3-ring PAHs was the highest. The spatial distribution of the ΣPAHs concentration was obvious, showing a decreasing tendency from south to north and from east to west. In the five soil types, the average concentrations of the ΣPAHs were relatively higher in the urban green space and the artificial forest, followed by the vegetable land, while the total PAH concentrations in paddy fields and corn fields were relatively lower and had no obvious spatial distribution differences. Source apportionment results studied using characteristic ratio analysis and factor analysis/multivariate linear regression showed that the main sources of PAHs in the topsoil of SNNA were mixed sources. Industrial coal combustion and motor vehicle exhaust were the main PAH contributors, with a combined contribution rate of 79.6%. The oil spill and coke oven contribution rate was about 16.2%, and the biomass fuel combustion was about 4.2%.

Gadolinium-chelate functionalized bismuth nanotheranostic agent for in vivo MRI/CT/PAI imaging-guided photothermal cancer therapy.

Multifunctional nanomaterials with simple structure and good biosafety, integrating multimodal imaging and therapeutic functions, can facilitate the development of clinical cancer treatments. Here, a simple but powerful pure bismuth based nanoparticle (Gd-PEG-Bi NPs) was developed from pure Bi NPs and gadolinium-diethylenetriaminepentaacetic acid-bis-tetradecylamide, which not only shows high quality MRI/CT/PAI triple-modal imaging, but can also be a potent photothermal therapy agent under the guidance of the triple-modal imaging. The Gd-PEG-Bi NPs showed good stability and excellent biocompatibility. In vitro and in vivo study demonstrated that Gd-PEG-Bi NPs have ultrahigh X-ray attenuation coefficient, short T1 relaxation time in MRI, and strong PAI signal. Following the imaging diagnosis, the excellent light-to-heat conversion efficiency of Gd-PEG-Bi NPs was capable of suppressing the tumor growth effectively under near-infrared laser radiation in vivo. Such multifunctional nanoparticles were ideal candidates for cancer diagnosis and treatment.

Near-infrared light-triggered theranostics for tumor-specific enhanced multimodal imaging and photothermal therapy.

The major challenge in current clinic contrast agents (CAs) and chemotherapy is the poor tumor selectivity and response. Based on the self-quench property of IR820 at high concentrations, and different contrast effect ability of Gd-DOTA between inner and outer of liposome, we developed "bomb-like" light-triggered CAs (LTCAs) for enhanced CT/MRI/FI multimodal imaging, which can improve the signal-to-noise ratio of tumor tissue specifically. IR820, Iohexol and Gd-chelates were firstly encapsulated into the thermal-sensitive nanocarrier with a high concentration. This will result in protection and fluorescence quenching. Then, the release of CAs was triggered by near-infrared (NIR) light laser irradiation, which will lead to fluorescence and MRI activation and enable imaging of inflammation. In vitro and in vivo experiments demonstrated that LTCAs with 808 nm laser irradiation have shorter T1 relaxation time in MRI and stronger intensity in FI compared to those without irradiation. Additionally, due to the high photothermal conversion efficiency of IR820, the injection of LTCAs was demonstrated to completely inhibit C6 tumor growth in nude mice up to 17 days after NIR laser irradiation. The results indicate that the LTCAs can serve as a promising platform for NIR-activated multimodal imaging and photothermal therapy.

MRI-guided tumor chemo-photodynamic therapy with Gd/Pt bifunctionalized porphyrin.

Porphyrin derivatives have been widely applied in MR imaging and photodynamic cancer therapy. We here report a novel Gd/Pt bifunctionalized porphyrin derivative (Gd/Pt-P1) for MRI-guided chemo-photodynamic cancer therapy. Gd/Pt-P1 was prepared from tetra(4-pyridyl) porphyrin (P1) via step by step coordination to cisplatin and gadolinium (Gd(iii)). Gd/Pt-P1 showed a particularly high synergetic chemo-photodynamic antitumor effect in vivo with a tumor inhibition rate (TIR) of 96.6% and excellent MR imaging performance.

[Effects of EDTA on lead accumulation in Tagetes patula and Salvia spendens].

Pot experiments were conducted to investigate the effects of EDTA on the Pb availability in rhizospheric soil and the Pb accumulation in Tagetes patula and Salvia spendens. The results showed that 7 days after applying EDTA (3.0 mmol x kg(-1)) into soil, the concentration of ammonium acetate (1 mol x L(-1)) -extracted Pb in rhizospheric soil increased significantly (P < 0.01), and the Pb content in T. patula and S. spendens leaves reached to 2415.88 and 1083.68 mg x kg(-1), being 61.36 and 5.37 times of the control, respectively. The Pb content also had a marked increase in T. patula and S. spendens stems, but had a slight decrease in their roots.

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture.

Soil contaminated with heavy metals cadmium (Cd) and lead (Pb) is hard to be remediated. Phytoremediation may be a feasible method to remove toxic metals from soil, but there are few suitable plants which can hyperaccumulate metals. In this study, Cd and Pb accumulation by four plants including sunflower (Helianthus annuus L.), mustard (Brassica juncea L.), alfalfa (Medicago sativa L.), ricinus (Ricinus communis L.) in hydroponic cultures was compared. Results showed that these plants could phytoextract heavy metals, the ability of accumulation differed with species, concentrations and categories of heavy metals. Values of BCF (bioconcentration factor) and TF (translocation factor) indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals. Changes on the biomass of plants, pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures. Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals, such as pH and Eh regulations, and so forth.