Diversity of medium and small-sized soil fauna community in different urban-rural green spaces and its influencing factors in Nanchang, China.

Urbanization is one of the important factors leading to biodiversity loss and habitat fragmentation. As an important component of urban ecosystem, soil fauna community plays a key role in improving soil structure and fertility, and promoting material circulation of urban ecosystem. To investigate the distribution characteristics of medium and small-sized soil fauna community in green space and the mechanisms underlying their responses to environmental change during urbanization, we selected 27 green space plots with a gradient of urban, suburban, and rural areas in Nanchang City as study objects, and measured plant parameters, soil physicochemical properties, and distribution characteristics of soil fauna community in these plots. The results showed that a total of 1755 soil fauna individuals were captured, belonging to 2 phyla, 11 classes, and 16 orders. The dominant groups were Collembola, Parasiformes, and Acariformes, which accounting for 81.9% of total soil fauna community. The density, Shannon diversity index, and Simpson dominance index of soil fauna community were significantly higher in suburban area than those in rural area. In the green space of the urban-rural gradient, there were large structure variations in different trophic levels of medium and small-sized soil fauna community. Herbivores and macro-predators occupied the largest proportion in rural area, and less in other areas. Results of the redundancy analysis showed the crown diameter, forest density, soil total phosphorus contents were the main environmental factors affecting soil fauna community distribution, with interpretation rate of 55.9%, 14.0% and 9.7%, respectively. Results of the non-metric multidimensional scale analysis showed that there were variations in soil fauna community characteristics in green space of the urban-rural gradient, and that the aboveground vegetation was the dominant factor for this change. This study improved our understanding of urban ecosystem biodiversity in Nanchang, and provided basis for maintaining soil biodiversity and urban green space construction.

Dominant protozoan species in rhizosphere soil over growth of Beta vulgaris L. in Northeast China.

This paper identified the dominant protozoan species in the four layers of rhizosphere soil during the six growth stages of Beta vulgaris L. and analyzed the correlations of the abundance and diversity of the dominant protozoan species with soil properties at different growth stages and soil depth. A total of 15 species of protozoa were identified; among them, Colpoda sp., Bodo sp., two kinds of Oxytricha sp., and Tachysoma sp. were the most dominant species of Beta vulgaris L. rhizosphere soil. The Colpoda sp. was eurytopic species in the Beta vulgaris L. rhizosphere soil and Tachysoma sp., Vorticella sp., Colpoda sp., Oxytricha sp.1, and Oxytricha sp. 2 were noted closely related to the acceleration function of circulation of N and P elements in soils. These dominant protozoan species were proposed to play a significant role of fertilization on N supply in rhizosphere soil during the initial growth of Beta vulgaris L.

Propafenone suppresses esophageal cancer proliferation through inducing mitochondrial dysfunction.

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with poor survival and limited therapeutic options. The aim of this study is to identify novel anticancer strategies from existing Food and Drug Administration (FDA)-approved drugs that have been used to clinically treat other diseases. Here, propafenone, an antiarrhythmic medication, was found to induce apoptosis and exert a significantly inhibitory effect on the proliferation and colony-forming ability of ESCC cells in a dose-dependent manner without observed cytotoxicity on normal esophageal epithelial cells. Furthermore, propafenone markedly suppressed growth of tumor xenografts in nude mice by reducing the Ki-67 proliferation index and angiogenesis but did not damage the vital organs of the animals. Mechanistically, our data from the proteomics, Western blot and flow cytometry analyses demonstrated that propafenone caused mitochondrial dysfunction as indicated by a decreased mitochondrial membrane potential and reduced expression of Bcl-xL and Bcl-2. In summary, this study provides the first evidence that propafenone, an FDA-approved drug to treat arrhythmias, could be a novel therapeutic strategy for treating ESCC without obvious side effects.

Isodeoxyelephantopin induces protective autophagy in lung cancer cells via Nrf2-p62-keap1 feedback loop.

Isodeoxyelephantopin (ESI), isolated from Elephantopus scaber L. has been reported to exert anticancer effects. In this study, we aimed to investigate whether and how cancer cells exert protective responses against ESI treatment. Confocal fluorescence microscopy showed that ESI significantly induced autophagy flux in the lung cancer cells expressing mCherry-EGFP-LC3 reporter. Treatment of the cells with ESI increased the expression levels of the autophagy markers including LC3-II, ATG3 and Beclin1 in a dose-dependent manner. Pretreatment with autophagy inhibitor 3-methyladenine (3-MA) not only attenuated the effects of ESI on autophagy, but also enhanced the effects of ESI on cell viability and apoptosis. Mechanistically, the SILAC quantitative proteomics coupled with bioinformatics analysis revealed that the ESI-regulated proteins were mainly involved in Nrf2-mediated oxidative stress response. We found that ESI induced the nuclear translocation of Nrf2 for activating the downstream target genes including HO-1 and p62 (SQSTM1). More importantly, ESI-induced p62 could competitively bind with Keap1, and releases Nrf2 to activate downstream target gene p62 as a positive feedback loop, therefore promoting autophagy. Furthermore, knockdown of Nrf2 or p62 could abrogate the ESI-induced autophagy and significantly enhanced the anticancer effect of ESI. Taken together, we demonstrated that ESI can sustain cell survival by activating protective autophagy through Nrf2-p62-keap1 feedback loop, whereas targeting this regulatory axis combined with ESI treatment may be a promising strategy for anticancer therapy.

[An outbreak of endemic typhus in Baoshan city, Yunnan province].

OBJECTIVE: To understand the epidemiologic characteristics of endemic typhus in Baoshan city. METHODS: Epidemiological data were collected and characteristics were analyzed. IgG antibody (Ab) of Rickettsia mooseri and Orientia tsutsugamushi in serum of patients were tested using both Weil-Felix and IFA method. The Rickettsia mooseri gltA gene, Rickettsia prowazekii gltA gene, Orientia tsutsugamushi 56 kDa protein gene, SFGR ompA gene, Ehrlichia sp. 16S rRNA gene and Anaplasma sp. 16S rRNA gene in spleen of mice were examined by PCR. RESULTS: Fifty-eight endemic typhus cases were found in Longyang district of Baoshan city, during July to August, 2009. Among them, 48 cases were confirmed by clinical diagnosis and 10 cases by laboratory tests. The Ab of Orientia tsutsugamushi Karp serotype was detected in 3 cases from laboratory diagnosis. The spleen samples from 85 Rattus flavipectus were tested using PCR. Of them, 3 samples for Rickettsia mooseri gltA gene showed positive (positive rate was 3.5%), and the homology of 3 Rickettsia mooseri and Rickettsia mooseri Wilmington strain (GenBank U59714.1) was 100% through comparing gene sequence. The results of PCR for detecting Rickettsia prowazekii, Orientia tsutsugamushi, SFGR, Anaplasma sp. and Ehrlichia. sp were all negative. CONCLUSION: The outbreak of endemic typhus was confirmed in Longyang district of Baoshan city through epidemiological data, clinical diagnosis and laboratory tests. Rickettsia mooseri DNA was detected in the dominant Rattus flavipectus, suggesting that endemic typhus did exist in the local areas.

[Survey on human rabies cases and its viral molecular biological features in Baoshan city, Yunnan province].

OBJECTIVE: To understand the epidemiological features of two rabies cases in Baoshan city year 2006 and 2007 and to analyze its source of infection. METHODS: Questionnaires were used to do the epidemiological survey on each of the rabies cases. Brain tissue samples of rabies patients were collect to detect the rabies virus by direct immunofluorescence assay (DFA) and RT-PCR assay. Homology and phylogenetic tree were analyzed, based on the whole nucleotide and deduced amino acid sequence of P, M and N gene of rabies virus followed by molecular epidemiological analysis. RESULTS: In July 2006, one human rabies case was identified in Longyang district, and another one in Tengchong county in Baoshan city in 2007. The degrees of exposure of these two patients was all at degree III. Two brain tissue samples among the dead patients (No. CYN0601H and CYN0701H) were confirmed positive by both DFA and RT-PCR assay. The homology analysis of P, M and N gene sequences among CYN0601H, CYN0701H and other rabies strains isolated from other provinces and other counties, showed that the samples in Baoshan city shared the highest homology with the strains in Thailand. Phylogenetic analysis indicated that the two samples were very close and all belonged to genetype 1 Lyssavirus, with the closest relationship between samples in Baoshan city and strains in Thailand. CONCLUSION: It was confirmed on the virus molecular level that the two patients in Baoshan city were both suffered from rabies. The prevalent strains in Baoshan city was probably imported from foreign country, suggesting that prevention and control measures on rabies virus in the boarder areas of Yunnan should be strengthened.