Mechanistic studies on protective effects of total flavonoids from Ilex latifolia Thunb. on UVB-radiated human keratinocyte cell line (HaCaT cells) based on network pharmacology and molecular docking technique.

The aim of the present research is to investigate anti-UVB radiation activity of total flavonoids from Ilex latifolia Thunb. (namely large-leaved Kuding tea) on human keratinocyte cell line (HaCaT cells) based on network pharmacology and molecular docking technique. Network pharmacology was used to screen target genes of active ingredients from Ilex latifolia Thunb. associated with UVB irradiation. The possible signaling pathways were analyzed by KEGG enrichment and verified by cellular experiments. Molecular docking was used to assess the affinity between the active ingredients and the core targets. The prediction of network pharmacology and molecular docking was identified by series experiment in UVB-irradiated HaCaT cells. Network pharmacology results showed that the active ingredients of Ilex latifolia Thunb. for anti-UVB irradiation were mainly flavonoids, and the possible signaling pathways were involved in PI3K-AKT, apoptosis, MAPKs, NF-κB, and JAK-STAT3. Molecular docking indicated key binding activity between AKT1-Glycitein, STAT3-Formononetin, CASP3-Formononetin, TNF-Kaempferol, CASP3-Luteolin, and AKT1-Quercetin. The total flavonoid pretreatment (0.25-1.0 mg/mL) down-regulated the expression of IL-6, IL-1ß, and TNF-α in the cells determined by ELISA. The expression of phosphor PI3K, phosphor AKT, phosphor JAK, phosphor STAT3, phosphor JNK, and phosphor p38 MAPKs and COX-2 proteins in cytosolic and NF-κB p65 protein in nucleus were down-regulated and determined by western blot. It also protected UVB-irradiated cells from apoptosis by reducing apoptosis rate and down-regulating active-caspase 3. In a word, the total flavonoid treatment protected HaCaT cells from UVB injuries effectively, and the potential mechanism involves PI3K-AKT, JAK-STAT3, MAPK, and NF-κB pathway by anti-inflammatory and apoptosis action in cells. The mechanism in vivo experiment needs to be further confirmed in future.

Protective effect of isoquercitrin on UVB-induced injury in HaCaT cells and mice skin through anti-inflammatory, antioxidant, and regulation of MAPK and JAK2-STAT3 pathways.

Natural products are favored in the study of skin photodamage protection recently. Isoquercetin, namely 3-O-glucoside of quercetin, can be isolated from various plant species. In present research, the protective effect of isoquercitrin on UVB-induced injury in cells and mice skin were investigated. Our study reveals that 400 µM of isoquercitrin exhibits the best viability on UVB-irradiated HaCaT cells, and beneficial effects against oxidative stress UVB-induced in skin tissue by decreasing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and simultaneously enhancing the activity of superoxide dismutase (SOD). Additionally, isoquercitrin was identified as an anti-inflammatory agent by reducing the level of COX-2 by Western blot analysis, and inflammatory cytokines such as IL-6, IL-1ß, and TNF-α by ELISA, and UVB-induced epidermal thickening evidenced by H&E staining. It also effectively prevented UVB-induced collagen fibers from degradation identified by Masson staining. Isoquercitrin significantly inhibited MAPK pathway by downregulating the levels of AP-1, MMP-1, MMP-3, phospho-p38, phospho-JNK, phospho-ERK, cleaved caspase-9, cleaved caspase-3, and JAK2-STAT3 pathway by western blot analysis. In conclusion, isoquercitrin pretreatment protected mice skin from UVB irradiation-induced injury effectively, and the underlying mechanism may involve MAPK and JAK2-STAT3 signaling pathways.

Risk factors for pathological upgrading in perimenopausal women with cervical intraepithelial neoplasia grade 2/3 following conization.

Postmenopausal women have a high risk for pathological upgrading in conization specimens due to pathological changes of the cervix. This study aimed to investigate the risk factors for pathological upgrading in conization specimens in Chinese women with cervical intraepithelial neoplasia grade 2/3 (Cervical intraepithelial neoplasia 2/3) ≥ 50 years of age. From January 2015 to December 2019, 443 CIN2/3 patients ≥ 50 years of age were retrospectively included and divided into the upgrade group (n = 47) and the non-upgrade group (n = 396) according to the presence or absence of pathological upgrading in the conization specimens. Multivariate logistic regression model was performed to analyze risk factors associated with pathological upgrading. The upgrade group was more likely to have gravidity < 2 times, postmenopausal period ≥ 5 years, higher incidences of endocervical glandular involvement (EGI) and human papillomavirus (HPV) 16/18 infection, as well as a lower incidence of cervical contactive bleeding and fewer cases undergoing endocervical curettage (all P < .05) than the non-upgrade group. Multivariate model showed that factors associated with pathological upgrading were postmenopausal period ≥ 5 years (OR = 2.55), EGI (OR = 17.71), endocervical curettage (OR = 0.33), and HPV type 16/18 (OR = 3.41) (all P < .05). The receiver operating characteristic analysis showed an area under curve of 0.782 (P < .001). Pathological upgrading in conization specimens is not uncommon in Chinese CIN2/3 patients ≥ 50 years of age. For those with high-risk factors of pathological upgrading (postmenopausal period ≥ 5 years, EGI, and HPV 16/18 infection), the follow-up interval can be appropriately shortened, and active intervention could be considered.

G protein-coupled estrogen receptor promotes acrosome reaction via regulation of Ca2+ signaling in mouse sperm†.

G protein-coupled estrogen receptor (GPER), a seven-transmembrane G protein-coupled receptor, mediates the rapid pre-genomic signaling actions of estrogen and derivatives thereof. The expression of GPER is extensive in mammal male reproductive system. However, the functional role of GPER in mouse sperm has not yet been well recognized. This study revealed that GPER was expressed at the acrosome and the mid-flagellum of the mouse sperm. The endogenous GPER ligand 17ß-estradiol and the selective GPER agonist G1 increased intracellular Ca2+ concentration ([Ca2+]i) in mouse sperm, which could be abolished by G15, an antagonist of GPER. In addition, the G1-stimulated Ca2+ response was attenuated by interference with the phospholipase C (PLC) signaling pathways or by blocking the cation channel of sperm (CatSper). Chlortetracycline staining assay showed that the activation of GPER increased the incidence of acrosome-reacted sperm. Conclusively, GPER was located at the acrosome and mid-flagellum of the mouse sperm. Activation of GPER triggered the elevation of [Ca2+]i through PLC-dependent Ca2+ mobilization and CatSper-mediated Ca2+ influx, which promoted the acrosome reaction of mouse sperm.

FAM83A Promotes the Proliferative and Invasive Abilities of Cervical Cancer Cells via Epithelial-Mesenchymal Transition and the Wnt Signaling Pathway.

The family with sequence similarity 83, member A (FAM83A) gene is associated with the occurrence and development of many malignant tumors. Our aim was to explore the role of FAM83A in cervical cancer. FAM83A was overexpressed or knocked down in cervical cancer cells, and the expressions of FAM83A, key proteins involved in the epithelial-mesenchymal transition (EMT), and Wnt signaling pathway-related proteins were detected by western blot analysis. Cell proliferative and invasive abilities were also examined using cell proliferation, colony formation, and Matrigel invasion assays. Cells were treated with the Wnt pathway inhibitor XAV-939 to determine whether Wnt signaling was necessary for the effect of FAM83A on cervical cancer cells. FAM83A was highly expressed in cervical cancer tissues and was associated with differentiation, TNM stage, lymph node metastasis, and poor prognosis in patients with cervical cancer. Knockdown of FAM83A inhibited the proliferation, colony formation, and invasion of cervical cancer cells. The opposite results were observed in FAM83A-overexpressing cells, and FAM83A overexpression also promoted EMT and Wnt signaling. XAV-939 reversed the activation of Wnt signaling and EMT induced by FAM83A. In conclusion, FAM83A expression was increased in cervical cancers and correlated with poor prognosis of patients. FAM83A overexpression can activate the Wnt signaling pathway, facilitate EMT, and promote the proliferative and invasive abilities of cervical cancer cells.

Combined Serum DKK3 and Circulating CD133 Cells as Prognostic Biomarkers for Ovarian Cancer Patients.

INTRODUCTION: Ovarian cancer (OV) can seriously endanger women's physical and mental health. Serum DKK3 has been used for the diagnosis and prognosis of patients with ovarian cancer. However, the specificity of antibodies may lead to errors in the detection of plasma protein. METHODS: Circulating CD133+ cells from blood samples were separated by magnetic microbeads. Serum DKK3 levels were determined by ELISA. The roles of DKK3 in OV cells were analyzed in vitro. RESULTS: In this study, we found that the CD133+ subpopulation in circulating tumor cells can indicate the overall survival rate of OV patients. Serum DKK3 levels were negatively correlated with the number of circulating CD133+ cells in OV patients. In addition, we confirmed the inhibitory effect of recombinant human DKK3 (rhDKK3) on OV cells via reversal of the epithelial-mesenchymal transition (EMT) process. CONCLUSION: Both serum DKK3 levels and circulating CD133+ tumor cells can be used as prognostic markers for patients with ovarian cancer.

[Molecular regulatory mechanisms of hypoxia-inducible factor and interventional effect of Chinese herbal medicine].

Hypoxia-inducible factors(HIFs)are the key transcription factors that sense and regulate cellular oxygen concentration in vivo. HIF-1 is composed of 2 subunits,α and ß,in which,the molecular regulatory mechanism of HIF-1α involves the main processes of its degradation and activation. The degradation of HIF-1α is regulated by oxygen-dependent pathways,including "von hippel-lindau protein(pVHL)-dependent pathway" and "pVHL-independent pathway". The activation of HIF-1α is regulated by oxygen-independent pathways,including mammalian target of rapamycin(mTOR)/eukaryotic initiation factor 4 E-binding protein 1(4 EBP1)/HIF-1α pathway,phosphatidylinositol 3-kinase(PI3 K)/proteirrserinc-threonine kinases(Akt)/HIF-1α pathway and silent information regulator1(Sirt1)/HIF-1α pathway. In recent years,based on the molecular regulatory mechanism of HIFs,Roxadustat,a new drug for the treatment of renal anemia has been developed. Besides, some macromolecular substances with similar pharmacological effect to HIFs have been found in the extracts from Chinese herbal medicine(CHM),such as emodin,notoginseng triterpenes,honokiol and clematichinenoside. These natural macromolecular substances play the regulatory roles in inflammatory response,epigenetic modification and auto-phagy. It is worth noting that,for common hypoxic-related diseases including diabetic kidney disease,HIFs-mediated "pyroptosis" may be a new target of CHMs for clearing dampness and heat and its representative classical prescriptions(Ermiao Pills)in treating inflammatory injury in cells and tissues.

hsa-microRNA-411-5p regulates proliferation, migration and invasion by targeting the hyaluronan mediated motility receptor in ovarian cancer.

The mortality rate of ovarian cancer is the highest out of all gynecological malignancies worldwide. Therefore, it is important to understand the mechanisms of ovarian cancer, identify new biomarkers and develop targeted drugs. The role and molecular mechanisms of hsa-microRNA (miR)-411-5p in ovarian cancer have not been fully elucidated. The present study investigated the ovarian cancer cell lines OVCAR-8 and SKOV3. After transfection with miRNA mimics, cell proliferation was monitored by a proliferation assay. Furthermore, cell migration was measured by a cell wound healing assay and cell invasion was measured by Matrigel invasion assays. A miRNA luciferase reporter assay was used to analyze the relationship between miRNAs and the target gene HMMR, which was then further evaluated by gene differential analysis. In the current study, hsa-mir-411-5p was identified as a miRNA regulator of the hyaluronan mediated motility receptor, which negatively regulated the activity of ERK1/2 and ultimately inhibited ovarian cancer cell proliferation and motility. Although hsa-mir-411-5p may have different roles in other types of cancer, the present study suggested that miR-411-5p functions as a negative tumor regulator in ovarian cancer cells, displaying the potential of miR-411-5p as a biomarker for ovarian cancer.

[Identification of cryptic structural chromosomal aberrations in parents through detection of copy number variations in miscarriage tissues].

OBJECTIVE: To explore the genetic cause for abnormal pregnancies through detecting chromosomal copy number variations (CNVs) in abortic tissues by next generation sequencing (NGS). METHODS: NGS technique was used to detect CNVs in abortion tissues. Parental chromosomal karyotypes were predicted based on the results. The aberrant chromosomal segments of the parents were accurately mapped by G-banding karyotyping analysis and fluorescence in situ hybridization (FISH). RESULTS: In addition to numerical chromosomal aberrations, 12 microdeletion/microduplications were detected by NGS. For 8 families where both parents accepted chromosomal karyotyping, 4 carriers of chromosomal abnormalities were identified. One marker chromosome was missed by karyotyping analysis, and a mother was confirmed to carry a cryptic balanced translocation by FISH. CONCLUSION: NGS can facilitate detection of cryptic chromosomal translocations in couples with repeated pregnancy failure and is of great value for detecting abnormal CNVs for its high sensitivity.

Association of C8orf4 expression with its methylation status, aberrant ß-catenin expression, and the development of cervical squamous cell carcinoma.

Chromosome 8 open reading frame 4 (C8orf4) is an activator of Wnt signaling pathway, and participates in the tumorigenesis and progression of many tumors. The expression levels of C8orf4 and ß-catenin were assessed via immunohistochemical staining in 100 cervical squamous cell carcinoma (CSCC) tissues, 50 high-grade squamous intraepithelial lesions (HSILs), 50 low-grade squamous intraepithelial lesions (LSILs), and 50 normal cervical tissues. Bisulfite sequencing polymerase chain reaction analysis was used to examine the methylation status of the C8orf4 locus in CSCC and normal cervical tissues. The expression rates of C8orf4 and ß-catenin were significantly higher in CSCCs or HSILs than in LSILs or normal cervical tissues (P < .05). C8orf4 expression was positively correlated with the poor differentiation of CSCCs (P = .009), and with aberrant expression of ß-catenin in CSCCs (P = .002) and squamous intraepithelial lesions (P < .001). The methylation rate of C8orf4 in CSCCs was significantly lower than that in normal cervical tissues (P = .001). The Cancer Genome Atlas genomics data also confirmed that the mRNA expression of C8orf4 was positively associated with the copy number alteration of C8orf4 (correlation coefficient = 0.213, P < .001), and negatively correlated with the methylation level of C8orf4 (correlation coefficient = -0.408, P < .001). In conclusion, the expressions of C8orf4 and ß-catenin were synergistically increased in CSCCs and HSILs and higher than those in LSILs and normal cervical tissues. The methylation level of C8orf4 is decreased in CSCCs and is responsible for the increased expression of C8orf4.

Protective effect of polysaccharide from Sophora japonica L. flower buds against UVB radiation in a human keratinocyte cell line (HaCaT cells).

Natured botanical extract has attracted considerable attention recently in the field of skin anti-ultraviolet (UV) radiation. As a medicinal herb, Sophora japonica flower buds contained several components such as flavonoids, isoflavonoids, triterpenes, alkaloids and polysaccharides, which have multiple pharmacological properties except hemostatic agents which have been used in China and Korea for centuries. The purpose of our study was to investigate whether polysaccharide extracted from Sophora japonica L. flower buds (PS) was able to attenuate UVB-induced damage using a human keratinocyte cell line (HaCaT cells). HaCaT cells were pretreated with PS in a serum-free medium for 2 h and then irradiated with different doses of UVB rays. The results showed that the PS attenuated UVB-induced cytotoxicity which was verified by MTT method and morphology feature assay. UVB exposure (30-120 mJ/cm2) reduced HaCaT cells viability significantly following with the increased irradiation dose 24 h later, while pretreatment with PS (0.25-2.0 mg/mL) attenuated UVB-induced cytotoxicity significantly and increased cell viability in a dose-dependent manner except 30 mJ/cm2 group. The PS reduced the ROS generation, down-regulated the expression of phosphor-JNK and phosphor-p38 MAPK proteins significantly through MAPK pathway in UVB-irradiated HaCaT cells. It also decreased the apoptosis rate at low dose of UVB ray and protected the cells from apoptosis which had been identified by the down-regulated level of active-caspase3 in UVB-irradiated HaCaT cells. In conclusion, PS pretreatment protected HaCaT keratinocytes from UVB irradiation-induced skin injuries effectively, and the underlying mechanism may involve MAPK signaling pathway which contribute to apoptotic cell death. However, further studies especially whose using human systems are needed to determine efficacy of PS in vivo.

Titania-coated 2D gold nanoplates as nanoagents for synergistic photothermal/sonodynamic therapy in the second near-infrared window.

The development of efficient nanomedicines to improve anticancer therapeutic effects is highly attractive. In this work, we firstly report titania-coated Au nanoplate (Au NPL@TiO2) heterostructures, which play dual roles as nanoagents for synergistic photothermal/sonodynamic therapy in the second near-infrared (NIR) window. On the one hand, because the controlled TiO2 shells endow the Au NPL@TiO2 nanostructures with a red shift to the NIR II region, the as-prepared Au NPL@TiO2 nanostructures possess a high photothermal conversion efficiency of 42.05% when irradiated by a 1064 nm laser and are anticipated to be very promising candidates as photothermal agents. On the other hand, the Au nanoplates (Au NPLs), as electron traps, vastly improve the generation of reactive oxygen species (ROS) by the Au NPL@TiO2 nanostructures in contrast with pure TiO2 shell nanoparticles upon activation by ultrasound (US) via a sonodynamic process. Moreover, the toxicity and therapeutic effect of the Au NPL@TiO2 nanostructures were relatively systemically evaluated in vitro. The Au NPL@TiO2 nanostructures generate a large amount of intracellular ROS and exhibit laser power density-dependent toxicity, which eventually induces apoptosis of cancer cells. Furthermore, a synergistic therapeutic effect, with a cell viability of only 20.3% upon both photothermal and sonodynamic activation, was achieved at low concentrations of the Au NPL@TiO2 nanostructures. Experiments on mice also demonstrate the superiority of the combination of PTT and SDT, with the total elimination of tumors. This work provides a way of applying two-dimensional (2D) gold nanoplate core/TiO2 shell nanostructures as novel nanoagents for advanced multifunctional anticancer therapies in the second NIR window.

Increased intracellular Cl- concentration promotes ongoing inflammation in airway epithelium.

Airway epithelial cells harbor the capacity of active Cl- transepithelial transport and play critical roles in modulating innate immunity. However, whether intracellular Cl- accumulation contributes to relentless airway inflammation remains largely unclear. This study showed that, in airway epithelial cells, intracellular Cl- concentration ([Cl-]i) was increased after Pseudomonas aeruginosa lipopolysaccharide (LPS) stimulation via nuclear factor-κB (NF-κB)-phosphodiesterase 4D (PDE4D)-cAMP signaling pathways. Clamping [Cl-]i at high levels or prolonged treatment with LPS augmented serum- and glucocorticoid-inducible protein kinase 1 (SGK1) phosphorylation and subsequently triggered NF-κB activation in airway epithelial cells, whereas inhibition of SGK1 abrogated airway inflammation in vitro and in vivo. Furthermore, Cl--SGK1 signaling pathway was pronouncedly activated in patients with bronchiectasis, a chronic airway inflammatory disease. Conversely, hydrogen sulfide (H2S), a sulfhydryl-containing gasotransmitter, confers anti-inflammatory effects through decreasing [Cl-]i via activation of cystic fibrosis transmembrane conductance regulator (CFTR). Our study confirms that intracellular Cl- is a crucial mediator of sustained airway inflammation. Medications that abrogate excessively increased intracellular Cl- may offer novel targets for the management of airway inflammatory diseases.

Cellular Mechanism Underlying Hydrogen Sulfide Mediated Epithelial K+ Secretion in Rat Epididymis.

As a novel gasotransmitter, hydrogen sulfide (H2S) elicits various physiological actions including smooth muscle relaxation and promotion of transepithelial ion transport. However, the pro-secretory function of H2S in the male reproductive system remains largely unclear. The aim of this study is to elucidate the possible roles of H2S in modulating rat epididymal intraluminal ionic microenvironment essential for sperm storage. The results revealed that endogenous H2S-generating enzymes cystathionine ß-synthetase (CBS) and cystathionine γ-lyase (CSE) were both expressed in rat epididymis. CBS located predominantly in epithelial cells whilst CSE expressed primarily in smooth muscle cells. The relative expression level of CBS and CSE escalated from caput to cauda regions of epididymis, which was paralleled to the progressively increasing production of endogenous H2S. The effect of H2S on epididymal epithelial ion transportation was investigated using short-circuit current (I SC), measurement of intracellular ion concentration and in vivo rat epididymal microperfusion. Our data showed that H2S induced transepithelial K+ secretion via adenosine triphosphate-sensitive K+ (KATP) channel and large conductance Ca2+-activated K+ (BKCa) channel. Transient receptor potential vanilloid 4 (TRPV4) channel-mediated Ca2+ influx was implicated in the activation of BKCa channel. In vivo studies further demonstrated that H2S promoted K+ secretion in rat epididymal epithelium. Inhibition of endogenous H2S synthesis caused a significant decrease in K+ concentration of cauda epididymal intraluminal fluid. Moreover, our data demonstrated that high extracellular K+ concentration actively depressed the motility of cauda epididymal sperm in a pH-independent manner. Collectively, the present study demonstrated that H2S was vital to the formation of high K+ concentration in epididymal intraluminal fluid by promoting the transepithelial K+ secretion, which might contribute to the maintenance of the cauda epididymal sperm in quiescent dormant state before ejaculation.

[Deletion of marker gene in transgenic goat by Cre/LoxP system].

In producing transgenic livestock, selectable marker genes (SMGs) are usually used to screen transgenic cells from numerous normal cells. That results in SMGs integrating into the genome and transmitting to offspring. In fact, SMGs could dramatically affect gene regulation at integration sites and also make the safety evaluation of transgenic animals complicated. In order to determine the deletion time and methods in the process of producing transgenic goats, the feasibility of deleting SMGs was explored by Cre/LoxP before or after somatic cell cloning. In addition, we compared the efficiency of protein transduction with plasmids co-transduction. We could delete 43.9% SMGs after screening out the transgenic cell clones, but these cells could not be applied to somatic cells cloning because of serious aging after two gene modifications. The SMG-free cells suitable for nuclear transfer were accessible by using the cells of transgenic goats, but this approach was more time consuming. Finally, we found that the Cre plasmid could delete SMGs with an efficiency of 7.81%, but about 30% in SMG-free cells had sequences of Cre plasmid. Compared with Cre plasmid, the integration of new exogenous gene could be avoided by TAT-CRE protein transduction, and the deletion rate of TAT-CRE transduction was between 43.9 and 72.8%. Therefore, TAT-Cre transduction could be an effective method for deleting selectable marker genes.

Seasonal and spatial variations in microbial community structure and diversity in the acid stream draining across an ongoing surface mining site.

This study examined the microbial community in an acidic stream draining across the Yun-Fu pyrite mine (Guangdong, China), where extremely acidic mine water is a persistent feature due to the intensive surface mining activities. Analysis of terminal restriction fragment length polymorphism (TRFLP) of 16S rRNA gene sequences showed that microbial populations varied spatially and seasonally and correlated with geochemical and physical conditions. After the stream moves from underground to the surface, the microbial community in the acidic water rapidly evolves into a distinct community close to that in the downstream storage pond. Comparisons of TRFLP peaks with sequenced clone libraries indicated that bacteria related to the recently isolated iron-oxidizer Ferrovum myxofaciens dominated the acidophilic community throughout the year except for the samples collected in spring from the storage pond, where Ferroplasma acidiphilum-like archaea represented the most abundant group. Acidithiobacillus ferrooxidans-affiliated organisms increased along the acid stream and remained common over the year, whereas Leptospirillum ferrooxidans-like bacteria were negligible or even not detected in the analyzed samples. The data indicate that changes in environmental conditions are accompanied by significant shifts in community structure of the prokaryotic assemblages at this opencast mining site.

Culturable and molecular phylogenetic diversity of microorganisms in an open-dumped, extremely acidic Pb/Zn mine tailings.

A combination of cultivation-based and molecular-based approaches was used to reveal the culturable and molecular diversity of the microbes inhabiting an open-dumped Pb/Zn mine tailings that was undergoing intensive acid generation (pH 1.9). Culturable bacteria found in the extremely acidic mine tailings were Acidithiobacillus ferrooxidans, Leptospirillum ferriphilum, Sulfobacillus thermotolerans and Acidiphilium cryptum, where the number of acidophilic heterotrophs was ten times higher than that of the iron- and sulfur-oxidizing bacteria. Cloning and phylogenetic analysis revealed that, in contrast to the adjacent AMD, the mine tailings possessed a low microbial diversity with archaeal sequence types dominating the 16S rRNA gene library. Of the 141 clones examined, 132 were represented by two sequence types phylogenetically affiliated with the iron-oxidizing archaea Ferroplasma acidiphilum and three belonged to two tentative groups within the Thermoplasma lineage so far represented by only a few environmental sequences. Six clones in the library were represented by the only bacterial sequence type and were closely related to the well-described iron-oxidizer L. ferriphilum. The significant differences in the prokaryotic community structures of the extremely acidic mine tailings and the AMD associated with it highlights the importance of studying the microbial communities that are more directly involved in the iron and sulfur cycles of mine tailings.

Copper and Zinc in a paddy field and their potential ecological impacts affected by wastewater from a lead/zinc mine, P. R. China.

As well known, at normal levels, copper and zinc are essential micronutrients for plants, animals, and humans. However, excessive Cu and Zn are toxic and disturb a wide range of biochemical and physiological processes. Using Atomic Absorption Spectrophotometer (AAS; Perkin-Elmer 3030, USA), soil and rice plant (Oryza sativa L.) samples collected from a paddy field in Lechang lead-zinc mine area, Guangdong Province, China were analyzed and their potential ecological impacts to local human and livestock were evaluated. The results showed that the paddy soils were contaminated with Cu and Zn. Both metals in soils had low bio-available fractions for paddy plants, animal and human by three chemically analytical techniques. Generally, were concentrations of copper and zinc root >> straw > stalk > grain with hull > grain without hull (i.e. unpolished rice) and in the normal ranges indicating no ecological risk for local livestock and residents. All positive correlation coefficients, however, between heavy metals in rice plant and total, exchangeable (step 1 in Tessier's method established in 1979) and DTPA-extractable fractions in soils were found in this study indicating that elevated heavy metal in soils would increase long-term exposition and possible consequence of ecological hazard through food chains.

Distribution patterns of octylphenol and nonylphenol in the aquatic system at mai po marshes nature reserve, a subtropical estuarine wetland in Hong Kong.

Spatial and temporal distribution of octylphenol (OP) and nonylphenol (NP) in Mai Po Marshes, a subtropical estuarine wetland in Hong Kong, were investigated. Surface water samples were collected every month from 11 sites during the period of September-December 2004. Concentrations of OP and NP ranged from 11.3 to 348 ng/L and from 29 to 2591 ng/L, respectively. The high levels of NP and OP were found in November and December than in September and October. The levels of OP and NP have no significant spatial differences except September. Total organic matter in the sediments appeared to be an important factor in controlling the fate of these compounds in the aquatic environment.

Cultivation-dependent and cultivation-independent characterization of the microbial community in acid mine drainage associated with acidic Pb/Zn mine tailings at Lechang, Guangdong, China.

Cultivation-based and molecular approaches were used to characterize the phylogenetic composition and structure of the microbial community in an extremely acidic (pH 2.0) acid mine drainage (AMD) associated with Pb/Zn mine tailings that were undergoing vigorous acid generation. Acidophilic bacteria were isolated and enumerated on solid media, and were found to be restricted to isolates related to Acidithiobacillus ferrooxidans and Acidiphilium cryptum. By contrast, cloning and phylogenetic analysis of 16S rRNA genes revealed that, although low in total taxonomically distinct groups, the tailings AMD ecosystem harbored a wide range of phylogenetically diverse microbes. Of the 141 clones examined, 104 were phylogenetically affiliated with the recently discovered, iron-oxidizing Leptospirillum group III within the Nitrospira. It thus appears that iron serves as the major electron donor in this habitat. Thirty clones were affiliated with the Proteobacteria, half of which belonged to organisms related to Alphaproteobacteria species capable of ferric iron reduction. Other clones were grouped with Betaproteobacteria and Gammaproteobacteria (six clones each), and even with Deltaproteobacteria (three clones), a subdivision with anaerobic sulfate or metal (iron) reduction as the predominant physiological trait of its members. Finally, four clones were clustered within the Firmicutes and the Acidobacteria. Approximately half of the sequence types representing the majority of the total clones fell into lineages that are poorly represented by cultured organisms or have thus far been represented by only a few environmental sequences. Thus, the present study extends our knowledge of the biodiversity of microorganisms populating highly acidic AMD environments.