Inconsistency and comprehensiveness of risk assessments for heavy metals in urban surface sediments

Numerous indices have been developed to assess environmental risk of heavy metals in surface sediments, including the total content based geoaccumulation index (I(geo)), exchangeable fraction based risk assessment code (RAC), and biological toxicity test based sediment quality guidelines (SQGs). In this study, the three indices were applied to freshwater surface sediments from 10 sections along an urbanization gradient of the Grand Canal, China to assess the environmental risks of heavy metals (Cu, Pb, Zn, Cd, and Cr) and to understand discrepancies of risk assessment indices and urbanization effects regarding heavy metal contamination. Results showed that Cd, Zn, and Pb were the most enriched metals in urban sections assessed by I(geo) and over 95% of the samples exceeded the Zn and Pb thresholds of the effect range low (ERL) of SQGs. According to RAC, Cu, Zn, Cd, and Cr had high risks of adversely affecting the water quality of the Grand Canal due to their remarkable portions of exchangeable fraction in surface sediment. However, Pb showed a relative low risk, and was largely bounded to Fe/Mn oxides in the urban surface sediments. Obviously, the three assessment indices were not consistent with each other in terms of predicting environmental risks attributed to heavy metals in the freshwater surface sediments of this study. It is recommended that risk assessment by SQGs should be revised according to availability and site specificity. However, the combination of the three indices gave us a comprehensive understanding of heavy metal risks in the urban surface sediments of the Grand Canal.

Secondary chondrosarcoma in the mandibular condyle

We report the case of a woman who had secondary chondrosarcoma in an osteochondroma in the left mandibular condyle, presenting as a large lobulated bone density mass in the left condyle process, to illustrate the clinical characteristics and imaging findings.

Climatic modifiers of the response to nitrogen deposition in peat-forming Sphagnum mosses: a meta-analysis

Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain. Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data. We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increased annual precipitation intensified the negative effects of N. The temperature effect was comparable to an experimental application of almost 4 g N m(-2)  yr(-1) for each 1°C increase. Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation.

First Report of Powdery Mildew of Hexinia polydichotoma Caused by Leveillula lactucae-serriolae in China

Hexinia polydichotoma (Ostenf) H.L. Yang (synonym Chondrilla polydichotoma Ostenf.) is an indigenous sand-binding plant that is widely distributed only in the desert regions of Northwest China. During the summer of 2007, severe outbreaks of a previously unknown powdery mildew were observed in the Taklimakan Desert in Xinjiang, China. Almost 95% of the plants surveyed were affected in this area. The upper surfaces of the stem were covered with white mycelia and the corresponding abaxial surfaces of infected leaves were chlorotic. Affected young, green stems also showed extended chlorosis. As the disease progressed, the infected stems turned yellow and necrotic. Heavy infection resulted in death of the plants. The primary conidia of the fungus were lanceolate with apical pointed, rarely cylindrical or subcylindrical with attenuated apex. They measured 53 to 73 × 15 to 21 μm and had a surface with a net of irregular rides and warts. Subcylindrical or subclavate secondary conidia with rounded ends measuring 50 to 77 × 13 to 20 μm were observed. The ascomata are subgregarious to scattered, globose, and 165 to 200 μm in diameter that are immersed in the dense mycelial tomentum. Numerous and well-developed appendages on the lower half of the ascomata are irregularly branched and can be as long as up to the ascomata diameter. The appendages measure 79 to 106 × 5 to 10 μm and are aseptate, thin walled, and smooth. Asci are numerous (usually more than 20 per ascoma), stalked, clavate-ovoid to nearly cylindrical, and contain two spores (rarely one or three). Ascospores are ellipsoid, hyaline, and measure 25 to 35 × 14 to 20 μm. On the basis of these characteristics, the fungus was identified as Leveillula lactucae-serriolae (2). A voucher specimen was deposited in the Herbarium of Martin Luther University, Halle, Germany (Accession No. HAL 2439F). To confirm the identification, the internal transcribed spacer (ITS) rDNA was amplified and sequenced, and deposited in GenBank (Accession No. HQ821500). Comparison with sequences available in the GenBank database revealed that the ITS sequence shares 99% similarity with that of L. lactucaeserriolae on Lactuca serriola from Iran (Accession No. AB044375.1) (1). Thus, the pathogen was identified as L. lactucae-serriolae based on the host plant species, anamorph morphology, and ITS sequence. Pathogenicity was confirmed through inoculation by gently pressing a diseased stem onto the stem of healthy H. polydichotoma plants. Five inoculated plants were kept under a plastic humid chamber, whereas the same number of noninoculated plants served as the control. The plants were placed under natural conditions (25 to 28°C) with 80 to 90% humidity. At 15 days after inoculation, typical symptoms of powdery mildew developed on the inoculated plants. No symptoms were seen on the control plants. To our knowledge, this is the first report of L. lactucaeserriolae in China and the first record of L. lactucae-serriolae on H. polydichotoma in the world ( http://nt.ars-grin.gov/fungaldatabases/index.cfm ). Because the plant is becoming widely cultivated in the Taklimakan Desert for use in sand-binding, the powdery mildew poses a serious threat to desertification control. References: (1) S. A. Khodaparast et al. Mycol Res. 105:909. 2001. (2) S. A. Khodaparast et al. Mycoscience 43:459, 2002.

Effects of Auxiliary Fiber Posts on Endodontically Treated Teeth With Flared Canals

Macro-Lock post combined with auxiliary fiber posts could increase the fracture resistance of endodontically treated roots with over-flared canals. However, an effect of the auxiliary fibers on retention strength was not observed.

First Report of Pomegranate Wilt Caused by Ceratocystis fimbriata in Sichuan Province

During May of 2009, a new devastating disease was observed on pomegranate (Punica granatum L.) that caused losses estimated at 30% as surveyed by 10 orchards in Panzhihua-Xichang Region of Sichuan Province, Southwest China. Characteristic symptoms were yellow and wilting leaves. Initial symptoms only occurred on shoots, but later, leaves of the whole tree turned yellow and wilted, causing extensive defoliation and dieback and the xylem of the trunk turned brown to black with a star burst-like pattern. Finally, heavy infection resulted in the whole tree dying, causing severe yield losses. A fungus was consistently isolated from basal stems and roots of diseased plants. Single conidia were obtained and cultured on potato dextrose agar (PDA) and incubated at 25 ± 1°C with a 12-h light/dark photoperiod. Mycelium was initially hyaline and then rapidly became dark greenish brown. Two types of endoconidia were produced in 5 days. Barrel-shaped conidia were hyaline, 1-celled, and measured 7.3 to 9.4 × 11.6 to 13.2 μm. Cylindrical conidia were hyaline, 1-celled, and measured 9.2 to 29.6 × 3.1 to 6.8 μm. Aleurioconidia were brownish, thick walled, near globose, and measured 8.7 to 18.1 × 8.2 to 10.7 μm. Perithecia were dark brown to black, globose, measured 90.8 to 149.8 μm in diameter, and had a long thin neck, 254.4 to 533.8 μm long, through which ascospores exuded. Ascospores were small, hyaline, hat shaped, measured 3.7 to 6.5 × 3.1 to 5.7 μm, and accumulated in a sticky matrix at the tip of the ascomal neck. The fungus was identified as Ceratocystis fimbriata (anamorph Chalara sp.) (1). The internal transcribed spacer (ITS) region of rDNA was amplified with universal primers ITS4/ITS5 and sequenced (GenBank Accession No. HQ529711), and comparisons with GenBank showed 99% similarity with C. fimbriata on Colocasia esculenta from Brazil (Accession No. AM712448.1). Pathogenicity tests were conducted. Two-week-old seedlings of pomegranate cv. Qingpiruanzi, germinated in plastic containers in the greenhouse, were wounded with a needle to a depth of 0.5 mm at the base of the stem below the soil level and near the root system, and then inoculated by drenching the wounds with a spore suspension (10⁵ conidia per ml). Control plants were inoculated with sterile water. There were four replicates for each treatment. The treated plants were incubated at 25 ± 1°C with 80 to 95% relative humidity under a 12-h light/dark photoperiod in a greenhouse. All inoculated plants wilted within 25 days after inoculation and C. fimbriata was reisolated. All control plants remained healthily. To our knowledge, this is the first finding of pomegranate wilt caused by C. fimbriata in Sichuan Province. This pathogen may pose a serious threat to pomegranate production in Sichuan where it is a major fruit tree. This pathogen has been previously reported in India (3) and Yunnan Province, China (2), but is not known elsewhere. References: (1) C. J. B. Engelbrecht and T. C. Harrington. Mycologia 97:57, 2005. (2) Q. Huang et al. Plant Dis. 87:1150, 2003. (3) Y. M. Somasekhara. Plant Dis. 83:400, 1999.

Experience with adrenal schwannoma in a Chinese population of six patients

OBJECTIVES

Benign adrenal schwannoma is an extremely uncommon cause of incidentaloma. This article describes our experience with the diagnosis and treatment of adrenal schwannoma in a Chinese population of 6 patients. To our knowledge, this is the largest series of this uncommon adrenal tumor treated in a single center.

METHODS

From May 1999 to May 2009, 6 patients with incidentally discovered adrenal schwannoma were operated on at a tertiary referral hospital in Eastern China. Clinical details, radiographic features, laboratory examinations, pathological findings, and follow-up data of these patients were analyzed.

RESULTS

Of the 6 patients, 4 were females (F) and 2 were males (M), with a mean age of 40.5 yr (range: 30-47, M:F=2:1). The 6 patients were managed with open unilateral adrenalectomy; 5 patients had schwannomas on the left side, and 1 on right side. Abnormal urine catecholamine was detected in 1 patient. The mean pathological size of these tumors was 4.3 ± 1.1 cm. The diagnosis of schwannoma was based on classic histological findings, and supported by immunohistochemistry of S-100, vimentin, and ABC positivity. In the follow- up of 47.5 ± 32.3 months, no recurrence and metastasis were observed.

CONCLUSIONS

Although there may be some clues for radiological diagnosis of adrenal schwannoma, preoperative misdiagnosis is not infrequent. Those tumors may occasionally have endocrine function. Histological examination is the key of diagnosis, and surgical resection is the treatment of choice once malignancy cannot be excluded by preoperative analyses.

Molecular cloning and characterization of a thioredoxin peroxidase gene from Apis cerana cerana

Thioredoxin peroxidases (Tpxs) play important roles in protecting organisms against the toxicity of reactive oxygen species (ROS) and regulating intracellular signal transduction. In the present study, we cloned the full cDNA of Tpx1 encoding a 195-amino acid protein from Apis cerana cerana (Acc). Based on the genomic DNA sequence, a 1442-bp 5'-flanking region was obtained, and the putative transcription factor binding sites were predicted. Quantitative PCR analysis showed that AccTpx1 was highly expressed in thorax and that the AccTpx1 transcript reached its highest level in two-week-old adult worker honeybees. Moreover, expression of the AccTpx1 transcript was increased by various abiotic stresses, such as ultraviolet light, HgCl(2) , and insecticide treatments. In addition, the recombinant AccTpx1 protein exhibited antioxidant activity; it removed hydrogen peroxide and protected DNA. These results suggest that AccTpx1 plays an important role in protecting honeybees from oxidative injury and may act in extending the lifespan of them.

Disulfiram modulated ROS-MAPK and NFκB pathways and targeted breast cancer cells with cancer stem cell-like properties

Background:

Previous studies indicate that disulfiram (DS), an anti-alcoholism drug, is cytotoxic to cancer cell lines and reverses anticancer drug resistance. Cancer stem cells (CSCs) are the major cause of chemoresistance leading to the failure of cancer chemotherapy. This study intended to examine the effect of DS on breast cancer stem cells (BCSCs).

Methods:

The effect of DS on BC cell lines and BCSCs was determined by MTT, western blot, CSCs culture and CSCs marker analysis.

Results:

Disulfiram was highly toxic to BC cell lines in vitro in a copper (Cu)-dependent manner. In Cu-containing medium (1 μM), the IC₅₀ concentrations of DS in BC cell lines were 200–500 nM. Disulfiram/copper significantly enhanced (3.7–15.5-fold) cytotoxicity of paclitaxel (PAC). Combination index isobologram analysis demonstrated a synergistic effect between DS/Cu and PAC. The increased Bax and Bcl2 protein expression ratio indicated that intrinsic apoptotic pathway may be involved in DS/Cu-induced apoptosis. Clonogenic assay showed DS/Cu-inhibited clonogenicity of BC cells. Mammosphere formation and the ALDH1^+VE and CD24^Low/CD44^High CSCs population in mammospheres were significantly inhibited by exposure to DS/Cu for 24 h. Disulfiram/copper induced reactive oxygen species (ROS) generation and activated its downstream apoptosis-related cJun N-terminal kinase and p38 MAPK pathways. Meanwhile, the constitutive NFκB activity in BC cell lines was inhibited by DS/Cu.

Conclusion:

Disulfiram/copper inhibited BCSCs and enhanced cytotoxicity of PAC in BC cell lines. This may be caused by simultaneous induction of ROS and inhibition of NFκB.

Cancer targeting Gene-Viro-Therapy of liver carcinoma by dual-regulated oncolytic adenovirus armed with TRAIL gene

Liver cancer is a common and aggressive malignancy, but available treatment approaches remain suboptimal. Cancer targeting Gene-Viro-Therapy (CTGVT) has shown excellent anti-tumor effects in a preclinical study. CTGVT takes advantage of both gene therapy and virotherapy by incorporating an anti-tumor gene into an oncolytic virus vector. Potent anti-tumor activity is achieved by virus replication and exogenous expression of the anti-tumor gene. A dual-regulated oncolytic adenoviral vector designated Ad·AFP·E1A·E1B (Δ55) (Ad·AFP·D55 for short thereafter) was constructed by replacing the native viral E1A promoter with the simian virus 40 enhancer/α-fetoprotein (AFP) composite promoter (AFPep) based on an E1B-55K-deleted construct, ZD55. Ad·AFP·D55 showed specific replication and cytotoxicity in AFP-positive hepatoma cells. It also showed enhanced safety in normal cells when compared with the mono-regulated vector ZD55. To improve the anti-hepatoma activities of the virus, the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene was introduced into Ad·AFP·D55. Ad·AFP·D55-TRAIL exhibited remarkable anti-tumor activities in vitro and in vivo. Treatment with Ad·AFP·D55-TRAIL can induce both autophagy owing to the Ad·AFP·D55 vector and caspase-dependent apoptosis owing to the TRAIL protein. Therefore, Ad·AFP·D55-TRAIL could be a potential anti-hepatoma agent with anti-tumor activities due to AFP-specific replication and TRAIL-induced apoptosis.

IL-10 polymorphisms and prostate cancer risk: a meta-analysis

Evidence is accumulating that chronic inflammation may have an important role in prostate cancer (PCa). Three common polymorphisms in the promoter of interleukin-10 (IL-10) gene, -1082 A>G, -819 C>T and -592 C>A, have been implicated to alter the risk of PCa, but the results of relative studies are inconclusive or controversial. To derive a more precise estimation of the relationship, we performed an updated meta-analysis on the basis of 10 studies. A comprehensive search was conducted to examine all the eligible studies of IL-10 polymorphism and PCa risk. We used odds ratios (ORs) to assess the strength of the association, and 95% confidence intervals (CIs) give a sense of the precision of the estimate. Overall, there were no significant associations between increased risk of PCa and IL-10 -1082 A>G, -819 C>T and -592 C>A polymorphisms. However, meta-analysis suggested that IL-10 -819 C>T and -592 C>A polymorphisms might be modestly associated with PCa aggressiveness (T versus C, OR=1.162, 95% CI: 1.035-1.305, P=0.011; A versus C, OR=1.131, 95% CI: 1.012-1.264, P=0.030; respectively). IL-10 -819 C>T and -592 C>A polymorphisms might impact PCa progression. Variant alleles at both -819 and -592 were modestly associated with advanced stages of PCa. Additional well-designed studies are warranted to validate these findings.

The Effects of Film Thickness and Texture on the high and Low-Field stress Response of Lead Zirconate Titanate Thin Films

Lead zirconate titanate (PZT) thin films are currently employed in non-volatile ferroelectric memories (FRAM's) and are intended to be used as the active material in a number of microelectromechanical systems (MEMS). Several groups have reported that both the piezoelectric and dielectric characteristics of ferroelectric thin films improve with an increase of film thickness, though the reasons for those improvements are unclear. Previous investigations on the effects of biaxial mechanical stress indicate that non-180° domain wall motion is limited in PZT 52/48 films less than 0.5 μm thick. It is possible that some of the improvements of the dielectric and piezoelectric characteristics reported for thicker films (i.e. films thicker than 0.5 μm) are associated with an increase of extrinsic contributions to the properties. To evaluate domain wall mobility in thicker films, the high and low-field stress response of sol-gel PZT fabricated with either rapid thermal processing or conventional furnace annealing were investigated. Films with thicknesses ranging from 0.6 to 5.0 μm thick were measured as a function of applied biaxial stress (±110 MPa). It was found that for all films tested the changes of capacitance were on the order of 2–3%. High-field measurements showed: (1) the coercive field to be insensitive to applied stress, (2) remanent polarizations to decrease about 20% at the maximum applied tension, (3) remanent polarizations to increase less than 10% with applied compression, and (4) all changes to be reversible over the stress range investigated. These results suggest that extrinsic contributions are limited for the films tested.

The fungicide ciclopirox inhibits lymphatic endothelial cell tube formation by suppressing VEGFR-3-mediated ERK signaling pathway

Ciclopirox olamine (CPX), an off-patent antifungal agent used to treat mycoses of skin and nails, has recently been demonstrated to be a potential anticancer agent. However, the underlying mechanism is not well understood. Here for the first time we show that CPX inhibited lymphangiogenesis in an in vitro model (tube formation). This effect was in part associated with inhibition of vascular endothelial growth factor receptor 3 (VEGFR-3) expression, as overexpression of VEGFR-3 conferred partial resistance to CPX inhibitory effect on tube formation in lymphatic endothelial cells (LECs), whereas downregulation of VEGFR-3 mimicked the effect of CPX, blocking the tube formation. Further study revealed that CPX did not alter mRNA level, but inhibited protein synthesis and promoted protein degradation of VEGFR-3. In addition, we found that CPX inhibited phosphorylation of the extracellular signal-related kinase 1/2 (ERK1/2), a downstream effector of VEGFR-3. Overexpression of VEGFR-3 attenuated CPX inhibition of ERK1/2 phosphorylation, whereas downregulation of VEGFR-3 inhibited extracellular signal-related kinase 1/2 (ERK1/2) phosphorylation in LECs. Ectopic expression of constitutively active mitogen -activated protein kinase kinase 1 (MKK1) resulted in activation of ERK1/2, and partially prevented CPX inhibition of LEC tube formation. The results suggest that CPX inhibits LEC tube formation at least in part through inhibiting VEGFR-3-mediated ERK signaling pathway.