[Clinical characteristics and risk factors of newly developed vertebral fractures after vertebral augmentation]

OBJECTIVE

To identify the characteristics and risk factors of the refractures after percutaneous kyphoplasty (PKP) and percutaneous vertebroplasty (PVP).

METHODS

A retrospective analysis of 148 patients who had undergone PKP or PVP between March 2006 and October 2013 in Peking University People's Hospital was conducted. In the study, 29 patients with 42 refractured vertebra and 119 patients without refracture were included. All the patients were observed for a time of (34.4±26.8) months. Clinical, imaging and procedure related factors (gender, age, height, weight, body mass index, the level of the injured vertebra, the time interval between the procedure and the refracture, the level of the refractured vertebra, the bone cement volume injected, performed PKP or PVP,performed unilateral or bilateral, the percentage of anterior vertebral height restoration, the correction of the Cobb angle, cement diffusion, bone mineral density, presence or absence of diabetes mellitus, history of fractures of the whole body, anti-osteoporosis treatment, cement leakage) for each group were analyzed by Cox proportional hazards regression analysis.

RESULTS

Of all the patients,16 (55.17%, 16/29) had refractures in the adjacent vertebra, and 13 (44.83%, 13/29) had refractures in the nonadjacent vertebra. Refractures within 3 months accounted for 31.03% (9/29) of all the refractures, and within 1 year accounted for 55.17% (16/29). Both older age (P=0.027, HR=1.051, 95% CI=1.006-1.098) and a history of fractures of the whole body (P=0.012, HR=0.386, 95% CI=0.184-0.812) were statistically significant as the independent risk factors for predicting refractures. Others were not associated with refractures (P>0.05).

CONCLUSION

Older age and a history of fractures of the whole body are the independent risk factors of the refractures after PKP and PVP. The mechanism of the refractures after PKP and PVP is mainly the natural development of osteoporosis.

[Applying percutaneous placement of guide wire combined with true lateral view fluoroscopy proximal femoral nail anti-rotation fixation]

OBJECTIVE

To apply modified proximal femoral nail anti-rotation (PFNA) fixation techniques performed by percutaneous placement of guide wire combined with true lateral view and to make the procedures simpler.

METHODS

A retrospective study was used to analyze the clinical data of femoral intertrochanteric fractures cases, which were treated with conventional PFNA fixation or modified PFNA fixation performed by percutaneous placement guide wire combined with true lateral view in our hospital, from March, 2011 to May, 2014. In the study, 60 cases were followed for average 13 months. The operation time, the amount of bleeding, the fluoroscopy time, postoperative radiographic measurements (tip apex distance, TAD) and hip function scores were analyzed.

RESULTS

In modified PFNA group, the amount of bleeding, the operation time and the fluoroscopy time were (34.9±6.1) mL, (70.5±12.5) min, (63.6±9.7) s respectively. In conventional PFNA group,they were (47.8±6.7) mL, (80.6±17.1) min, (68.5±8.7) s respectively. There were significant differences in the above respects between the two groups (P were 0.006, 0.013, and 0.022 respectively). There were no significant differences in TAD, fracture healing time, postoperative hip scores between the two groups (P>0.05).

CONCLUSION

Fracture line is a natural entry point for some cases of femoral intertrochanteric fractures when we use proximal femoral nail anti-rotation to fix the fracture. Applying percutaneous insertion of the guide pin combined with true lateral view could reduce the operation time, amount of bleeding, and fluoroscopy time significantly, make the procedures simpler and acquire satisfactory results .

Analysis of apoptosis induced by perfluorooctane sulfonates (PFOS) in mouse Leydig cells in vitro

To explore the possible mechanism of perfluorooctane sulfonates (PFOS's) reproductive toxicity, mouse Leydig cells cultured in vitro were exposed to a serial concentration of PFOS for four more days of culture. Apoptosis during the process was checked. After 24 h, apoptosis occurred to all of the groups ≥ 50 μg/mL PFOS. After 72 h, 37.5 μg/mL dose also showed apoptosis, and the most apoptosis signals, averagely 18 per well, were observed in 62.5 μg/mL dose group. An increase in ROS (p < 0.05) and a decrease of mitochondrial membrane potential (p < 0.01) was confirmed in those groups with ≥ 12.5 μg/mL dose. ROS levels peaked in 50 μg/mL and 62.5 μg/mL groups, nearly two-folds higher than control. PFOS was also observed to down-regulate the protein expression of Bcl-2 and to up-regulate that of Bax. The apoptosis induced by PFOS in mouse Leydig cells was shown to be related to mitochondrially mediated pathways and to involve oxidative stress.

[Correlation between aquatic plant diversity and water environment in the typical sites of Hangzhou section of the Beijing-Hangzhou Grand Canal]

Community characteristics of aquatic plant are important indicators for water quality. In order to understand the distribution characteristics of aquatic plants in aquatic ecosystem of the Beijing-Hangzhou Grand Canal ( Hangzhou section) , and to analyze the relationship between water quality and plant community, an investigation of the aquatic plants in five typical sites was made in this study. Species composition, biological diversity, quantity distribution and dominant species of aquatic plants in five sites were studied for ecological changes. Physicochemical factors such as temperature, pH value, transparency, dissolved oxygen and main elements of living were also analyzed. Based on the results, the distribution of phytoplankton diversity and environment factor correlations by multivariate statistical analysis were discussed. The trophic levels of these sites were assessed by using related biological standards. Results indicated that the diversity of aquatic plant mainly depends on the diversity of phytoplankton in the typical sites of the Beijing-Hangzhou Grand Canal. We observed and identified 35 genus algae, including advantage community of Hyalodiscus Ehrenberg and Melosira Agardh, which belonged to Bacillariophyta. According to the impact on the phytoplankton diversity and distribution, factors such as dissolved oxygen, transparency, water temperature, etc. had an obvious influence on the distribution of phytoplankton in the existing 6 environmental factors, while the influence of pH value was the highest. In terms of water quality eutrophication, site Tangxi Bridge and Maiyu Bridge showed a relatively lighter pollution, while site Yiqiao Bridge, Gujia Bridge and Gongchen Bridge showed a higher pollution, and the pollution of site Yiqiao Bridge was the most serious.

Prognostic value of CpG island methylator phenotype among colorectal cancer patients: a systematic review and meta-analysis

BACKGROUND

Divergent findings regarding the prognostic value of CpG island methylator phenotype (CIMP) in colorectal cancer (CRC) patients exist in current literature. We aim to review data from published studies in order to examine the association between CIMP and CRC prognosis.

MATERIALS AND METHODS

A comprehensive search for studies reporting disease-free survival (DFS), overall survival (OS), or cancer-specific mortality of CRC patients stratified by CIMP is carried out. Study findings are summarized descriptively and quantitatively, using adjusted hazard ratios (HRs) as summary statistics.

RESULTS

Thirty-three studies reporting survival in 10 635 patients are included for review. Nineteen studies provide data suitable for meta-analysis. The definition of CIMP regarding gene panel, marker threshold, and laboratory method varies across studies. Pooled analysis shows that CIMP is significantly associated with shorter DFS (pooled HR estimate 1.45; 95% confidence interval (CI) 1.07-1.97, Q = 3.95, I(2) = 0%) and OS (pooled HR estimate 1.43; 95% CI 1.18-1.73, Q = 4.03, I(2) = 0%) among CRC patients irrespective of microsatellite instability (MSI) status. Subgroup analysis of microsatellite stable (MSS) CRC patients also shows significant association between shorter OS (pooled HR estimate 1.37; 95% CI 1.12-1.68, Q = 4.45, I(2) = 33%) and CIMP. Seven studies have explored CIMP's value as a predictive factor on stage II and III CRC patient's DFS after receiving adjuvant 5-fluorouracil (5-FU) therapy: of these, four studies showed that adjuvant chemotherapy conferred a DFS benefit among CIMP(+) patients, one concluded to the contrary, and two found no significant correlation. Insufficient data was present for statistical synthesis of CIMP's predictive value among CRC patients receiving adjuvant 5-FU therapy.

CONCLUSION

CIMP is independently associated with significantly worse prognosis in CRC patients. However, CIMP's value as a predictive factor in assessing whether adjuvant 5-FU therapy will confer additional survival benefit to CRC patients remained to be determined through future prospective randomized studies.

Effects of subchronic samarium exposure on the histopathological structure and apoptosis regulation in mouse testis

To evaluate the reproductive toxicity of samarium, a widely used rare earth element, male ICR mice were orally exposed to samarium nitrate for 90 days for lesion evaluation in the testis. Decreased organ coefficients, disorganized seminiferous tubules, and decreased spermatogenic cells and sperm of the testis were observed extensively in the treated groups, indicating that the testis is a target organ of samarium. Electron microscopy confirmed that the lesions inside the spermatogenic cells and sperm mainly included mitochondrial swelling, mitochondrial vacuolization, fuzzy nuclear membranes, and marginated chromatin. Increased spermatogenic cell apoptosis rate in the testis was confirmed with a TUNEL assay. And expression up-regulation of p53 and Bax, and down-regulation of Bcl-2 were observed (p<0.05), indicating the apoptosis is related to p53 mediated pathway.

Ultrasound-assisted extraction and purification of schisandrin B from Schisandra chinensis (Turcz.) Baill seeds: optimization by response surface methodology

The objective of this study is to develop a process consisting of ultrasonic-assisted extraction, silica-gel column chromatography and crystallization to optimize pilot scale recovery of schisandrin B (SAB) from Schisandra chinensis seeds. The effects of five independent variables including liquid-solid ratio, ethanol concentration, ultrasonic power, extraction time, and temperature on the SAB yield were evaluated with fractional factorial design (FFD). The FFD results showed that the ethanol concentration was the only significant factor for the yield of SAB. Then, with the liquid-solid ratio 5 (mL/g) and ultrasonic power 600 W, the other three parameters were further optimized by means of response surface methodology (RSM). The RSM results revealed that the optimal conditions consisted of 95% ethanol, 60 °C and 70 min. The average experimental SAB yield under the optimum conditions was found to be 5.80 mg/g, which was consistent with the predicted value of 5.83 mg/g. Subsequently, a silica gel chromatographic process was used to prepare the SAB-enriched extract with petroleum ether/acetone (95:5, v/v) as eluents. After final crystallization, 1.46 g of SAB with the purity of 99.4% and the overall recovery of 57.1% was obtained from 400 g seeds powder. This method provides an efficient and low-cost way for SAB purification for pharmaceutical industrial applications.

Elevated cell proliferation and VEGF production by high-glucose conditions in Müller cells involve XIAP

PURPOSE

Müller cells have important roles in the pathogenesis of diabetic retinopathy by promoting cell proliferation and inducing the production of vascular endothelial growth factor (VEGF) under hyperglycemic conditions. The objective of this study was to determine the potential mechanism of Müller cell proliferation and VEGF production due to high-glucose conditions.

METHODS

Primary cultured rat Müller cells were incubated with medium containing variable concentrations of glucose and/or embelin, a specific inhibitor of X-linked inhibitor of apoptosis protein (XIAP), for 72 h. The proliferation of Müller cells was assessed by the MTT assay. The expression and/or phosphorylation of 146 proteins were assessed using protein pathway array.

RESULTS

High concentrations of glucose-induced Müller cell proliferation and altered expression and/or phosphorylation of 47 proteins that have been identified to have key roles in several important signaling pathways (XIAP, VEGF, HIF1α, NFκB, etc) and are involved in the regulation of cell survival, proliferation, or apoptosis. However, Müller cell alterations induced by high-glucose conditions were counteracted by the XIAP inhibitor embelin, and 26 proteins/phosphorylations (out of 47) were restored to their normal levels. Nine proteins, including NFκB p65, p-p38, tumor necrosis factor-α, urokinase-type plasminogen activator, CREB, IL-1β, HCAM, estrogen receptor-α, and p-Stat3, were involved in regulatory networks between XIAP and VEGF.

CONCLUSIONS

The current study suggests that XIAP may be a potential regulator that can mediate a series of pathological changes induced by high-glucose conditions in Müller cells. Therefore, embelin could be a potential agent for the prevention and treatment of diabetic retinopathy.

Ox-LDL increases OX40L in endothelial cells through a LOX-1-dependent mechanism

Oxidative low-density lipoprotein (Ox-LDL) is a key risk factor for the development of atherosclerosis, and it can stimulate the expression of a variety of inflammatory signals. As a new and highly sensitive inflammation index, OX40L may be a key to understanding the mechanisms that regulate interactions between cells within the vessel wall and inflammatory mediators during the development of atherosclerosis. To investigate whether Ox-LDL regulates OX40L expression through an oxidized LDL-1 receptor (LOX-1)-mediated mechanism, we investigated the effect of different concentrations of Ox-LDL (50, 100, 150 µg/mL) on endothelial cell proliferation and apoptosis. Stimulation with Ox-LDL increased OX40L protein 1.44-fold and mRNA 4.0-fold in endothelial cells, and these effects were inhibited by blocking LOX-1. These results indicate that LOX-1 plays an important role in the chronic inflammatory process in blood vessel walls. Inhibiting LOX-1 may reduce blood vessel inflammation and provide a therapeutic option to limit atherosclerosis progression.

Aqueous two-phase system coupled with ultrasound for the extraction of lignans from seeds of Schisandra chinensis (turcz.) Baill

In this study the potential use of an aqueous two phase system (ATPS) coupled with ultrasound for the extraction of lignans from Schisandra chinensis seeds was evaluated and optimized using response surface methodology (RSM). The main bioactive components, schizandrin (SA), schisantherin A (SAA) and deoxyschizandrin (DSA) were selected as markers. The partitioning behavior of lignans in different salt-types of ATPS was compared. The optimization ATPS of 25% (w/w) (NH(4))(2)SO(4) and 19% (w/w) ethanol were selected based on their higher upper phase partitioning coefficient (>74) and the recovery (>93%) for three markers. Using the optimized ATPS solvent, the RMS results showed 20:1 of solvent:solid, 800 W and 61.1 min were the optimal ultrasound assisted extraction conditions, under which 13.10mg/g SA, 1.87 mg/g SAA and 1.84 mg/g DSA were recovered in the upper phase, whereas the wasted stigmas accumulated in the lower phase. Compared with 80% ethanol (v/v) ultrasonic extraction, similar yields were obtained, but the present method exhibited higher extraction purity for the selective extraction of lignans from S. chinensis seeds.

Abstract P2-05-19: Pathway-based analysis of breast cancer

Objective: Although HER2 and ER pathways are predominant pathways altered in breast cancer, it is now well accepted that many other signaling pathways are also involved in the pathogenesis of breast cancer, especially in triple negative breast cancer. The understanding of these additional pathways may assist in identifying new therapeutic approaches for breast cancer.

Methods: 13 invasive ductal carcinoma tissues and 5 benign breast tissues were analyzed for the mRNA expression level of 1243 cancer pathway-related genes using SmartChip (WaferGen, CA), a real-time PCR-base method. In addition, the levels of 154 cancer pathway-related proteins and phosphoproteins were measured using our innovative Protein Pathway Array.

Results: Out of 1,243 mRNAs, 68.7% were detected in breast cancer and 73 mRNAs were statistically significant between benign and cancer tissues. Of these mRNAs, 105 only expressed in breast cancer tissues and 33 mRNAs only expressed in normal breast tissues. Out of 154 proteins and phosphoproteins, 39% were detected in cancer tissues and 50 proteins were significantly differentiated between tumor and normal tissues. Interestingly, only 3 genes (CDK6, Vimentin and SLUG) showed decrease of both protein and mRNA. Six proteins (BCL6, CCNE1, PCNA, PDK1, SRC and XIAP) showed differentially expressed between tumor and normal tissues but no differences were observed at mRNA levels. Analyses of mRNA and protein data using Ingenuity Pathway Analysis showed more 15 pathways were altered in breast cancers and 6 of them shared between mRNAs and proteins, including p53, IL17, HGF, NGF, PTEN and PI3K/AKT.

Conclusion: There is a broad dysregulation of various pathways in breast cancer both at protein levels and mRNA levels. It is important to note that mRNA expression does not correlate with protein level, suggesting that different regulation mechanisms between proteins and mRNAs.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-05-19.

An ammonium sulfate/ethanol aqueous two-phase system combined with ultrasonication for the separation and purification of lithospermic acid B from Salvia miltiorrhiza Bunge

We studied the effect of ultrasonication extraction technology combined with ammonium sulfate/ethanol aqueous two-phase system (ATPS) for the separation of lithospermic acid B (LAB) from Salvia miltiorrhiza Bunge. According to the literature and preliminary studies, ammonium sulfate concentration, ethanol concentration, pH, ultrasonication power, ultrasonication time and the ratio of solvent-to-solid were investigated using a single factor design to identify the factors affecting separation. Taking into consideration a simultaneous increase in LAB recovery (R (%)) and partition coefficient (K), the best performance of the ATPS was obtained at 25°C and pH 2 using ammonium sulfate 22% (w/w) and ethanol 30% (w/w). To keep the solvent-to-solid ratio at 10, response surface methodology was used to find the optimal ultrasonication power and ultrasonication time. Quadratic models were predicted for LAB yield in the upper phase. Optimal conditions of 572.1 W ultrasonication power and 42.2 min produced a maximum yield of LAB of 42.16 mg g(-1) sample. There was no obvious degradation of LAB with ultrasound under the applied conditions, and the experimental yield of LAB was 42.49 mg g(-1) sample and the purity was 55.28% (w/w), which was much higher than that obtained using conventional extraction. The present study demonstrated that ultrasound coupled with aqueous two-phase systems is very efficient tool for the extraction and purification of LAB from Salvia miltiorrhiza Bunge.

Epidermal growth factor receptor tyrosine kinase regulates the human inward rectifier potassium K(IR)2.3 channel, stably expressed in HEK 293 cells

BACKGROUND AND PURPOSE

The detailed molecular modulation of inward rectifier potassium channels (including the K(IR) 2.3 channel) is not fully understood. The present study was designed to determine whether human K(IR) 2.3 (K(IR) 2.3) channels were regulated by protein tyrosine kinases (PTKs).

EXPERIMENTAL APPROACH

Whole-cell patch voltage-clamp, immunoprecipitation, Western blot analysis and site-directed mutagenesis were employed to determine the potential PTK phosphorylation of Kir2.3 current in HEK 293 cells stably expressing Kir2.3 gene.

KEY RESULTS

The broad-spectrum PTK inhibitor genistein (10 µM) and the selective epidermal growth factor (EGF) kinase inhibitor AG556 (10 µM) reversibly decreased K(IR) 2.3 current and the effect was reversed by the protein tyrosine phosphatase inhibitor, orthovanadate (1 mM). Although EGF (100 ng·mL(-1) ) and orthovanadate enhanced K(IR) 2.3 current, this effect was antagonized by AG556. However, the Src-family tyrosine kinase inhibitor PP2 (10 µM) did not inhibit K(IR) 2.3 current. Tyrosine phosphorylation of K(IR) 2.3 channels was decreased by genistein or AG556, and was increased by EGF or orthovanadate. The decrease of tyrosine phosphorylation of K(IR) 2.3 channels by genistein or AG556 was reversed by orthovanadate or EGF. Interestingly, the response of K(IR) 2.3 channels to EGF or AG556 was lost in the K(IR) 2.3 Y234A mutant channel.

CONCLUSION AND IMPLICATIONS

These results demonstrate that the EGF receptor tyrosine kinase up-regulates the K(IR) 2.3 channel via phosphorylation of the Y234 residue of the WT protein. This effect may be involved in the endogenous regulation of cellular electrical activity.

Expressed sequence tag-simple sequence repeat-based molecular variance in two Salicornia (Amaranthaceae) populations

Salicornia spp is one of the most salt-tolerant vascular plants and is native to salt marshes and estuaries. We developed expressed sequence tag derived-simple sequence repeat (EST-SSR) markers for estimating genetic diversity and marker-assisted Salicornia breeding. Six polymorphic EST-SSRs of 40 detected 27 alleles, ranging from three to five alleles per locus. The average number of alleles per locus was 4.33 and 4.17, and the major allele frequency at locus DY529765 was high, being 0.859 and 0.857 in S. bigelovii and S. europea, respectively. Gene diversity, heterozygosity and polymorphism information content were highest at locus DY529950 and similar in these two species. Gene diversity increased with increase in the number of alleles that had a low major allele frequency at a locus. Six polymorphic loci effectively discriminated 46 taxa into three clusters via different analyses. Significant deviation of F(ST) from zero in three suggested populations for six loci indicated population differentiation and limited gene flow among them. A reduced median network established that taxon SB65 is primitive. SMART (simple modular architecture research tool) analysis of peptide sequences of six EST-SSRs showed that loci DY529765, DY529950 and EC906203 contained transmembrane, TLC, AgrB and NTR domains and might be involved in salinity stress tolerance. These EST-SSRs are a valuable resource for marker development and may be useful in marker-assisted Salicornia breeding.

One-year monthly survey of rotavirus, astrovirus and norovirus in three sewage treatment plants (STPs) in Beijing, China and associated health risk assessment

To evaluate the presence and distribution of the three main viruses (rotavirus, astrovirus, and norovirus) responsible for human acute gastroenteritis in sewerage systems, a one-year study was carried out in Beijing, China. A total of 96 samples of influent and effluents from three sewage treatment plants (STPs) were collected from November 2006 to October 2007. Silica was used to concentrate viral particles from water samples and a reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) method was used for detection of viruses. Virus(es) could be detected in 35.4% (34/96) of the water samples analysed, where human rotavirus was the most frequently detected one (32.3%, 31/96), followed by human astrovirus (6.3%, 6/96) and human norovirus (3.1%, 3/96). According to the quantitation results of rotaviruses, which were gained by the real-time quantitative RT-PCR method with SYBR Green I, it was known that the distributions of rotaviruses in influents and effluents of three STPs were quite similar, i.e., abundant in cold weather (from October to March) and less prevalent in warm weather (from April to September). According to the estimated exposure dose and exposure frequency, as well as the acceptable annual risk level, it was shown that the rotaviruses in the reused wastewater after conventional treatment process presented potential risk to human health through both occupational and accidental exposure.

One-year monthly survey of rotavirus, astrovirus and norovirus in three sewage treatment plants in Beijing, China and associated health risk assessment

To evaluate the presence and distribution of the three main viruses (rotavirus, astrovirus, and norovirus) responsible for human acute gastroenteritis in sewerage system an one-year study was carried out in Beijing, China. A total of 96 samples of influent and effluents from three sewage treatment plants (STPs) were collected from November 2006 to October 2007. Silica was used to concentrate viral particles from water samples and a reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) method was used for detection of viruses. Viruses could be detected in 35.4% (34/96) of the water samples analyzed, where human rotavirus was the most frequently detected (32.3%, 31/96), followed by human astrovirus (6.3%, 6/96) and human norovirus (3.1%, 3/96). According to the quantitation results of rotaviruses, which were gained by the real-time quantitative RT-PCR method with SYBR Green I , it was known that the distributions of rotaviruses in influents and effluents of three STPs were quite similar, i.e., abundant in cold weather (from October to March) and less prevalent in warm weather (from April to September). According to the estimated exposure dose, exposure frequency, as well as the acceptable annual risk level, it was shown that the rotaviruses in the reused wastewater after conventional treatment process presented potential risk to human health through both occupational and accidental exposure.

Annexin A1 expression and its prognostic significance in human breast cancer

Annexin A1 (ANXA1) is a calcium- and phospholipid-binding protein and is considered to play an important role in tumorigenesis. However, the correlation between ANXA1 expression and tumor clinicopathological features in patients with breast cancer remains unclear. This study investigated the prognostic value of ANXA1 protein as breast cancer marker. Tissue microarray blocks, containing 20 cases of non-tumor breast tissue, 20 cases of benign breast lesion and 135 cases of breast cancer (107 with lymph node metastasis), were constructed. Expression of ANXA1 in these specimens was analyzed using immunohistochemistry. In non-tumor tissue and benign breast lesions, myoepithelial cells showed strong expression of ANXA1. Negative ANXA1 expression was significantly associated with advanced disease stage (P<0.05), especially pathological-N stage (P<0.01). The patients with loss of ANXA1 expression in tumor tissues showed a significantly worse overall survival compared with positive ones (P<0.05). ANXA1 did not correlate well with estrogen receptor (ER), progesterone receptor (PR) and HER2/neu status. Moreover, the level of ANXA1 expression in lymph node metastases was higher than corresponding primary breast cancer. These results suggest that ANXA1 may play a multifaceted role in breast cancer development, progression, and metastases.

The effect of soil organic matter on fate of polycyclic aromatic hydrocarbons in soil: A microcosm study

A microcosm study was conducted to address the influences of air-soil partition and sequestration on the fate of polycyclic aromatic hydrocarbons (PAHs) in soil. Sterilized and unsterilized soils with soil organic carbon (SOC) content ranging from 0.23 to 7.06% were incubated in a chamber with six PAHs supplied through air. After 100 d of incubation when the system approached pseudo-steady state, the PAHs concentrations in the unsterilized soils still correlated with SOC significantly, while the association did not exist for those sterilized. The lower degradation rate in the soil with higher SOC was likely the major reason for the association between SOC and PAHs concentrations, while the decreased surface porosity likely suppressed such correlation for the sterilized samples. The results indicated that the sequestration was likely the major mechanism for the accumulation of PAHs in soils, while both of the soil porosity and PAHs properties had observed influences.

First molecular detection of group A rotaviruses in drinking water sources in Beijing, China

The most prevalent group A rotavirus found in the diarrheic children was also determined in drinking water sources including raw water, treated water and tap water in Beijing, and then the possible contamination contributions to tap water for human consumption were discussed in this study. A total of 26 raw water samples, 77 treated water samples and 143 tap water samples in Beijing were collected for analysis of group A rotavirus from April 2006 to August 2007. According to the results, it was shown that group A rotaviruses occurred in 9 raw water samples (34.6%), 9 treated water samples (11.7%) and 32 tap water samples (22.4%) during the sampling period, and low disinfectant residuals or a vulnerability of the distribution system to pressure transients, in addition to raw water, may account for the group A rotaviruses contamination to tap water. The rotavirus contamination observed in this study may highlight a potential public health risk and illustrate the importance of including routine virological analysis of drinking water supplies during winter time in Beijing.