Cab45S inhibits the ER stress-induced IRE1-JNK pathway and apoptosis via GRP78/BiP

Disturbance of endoplasmic reticulum (ER) homeostasis causes ER stress and leads to activation of the unfolded protein response, which reduces the stress and promotes cell survival at the early stage of stress, or triggers cell death and apoptosis when homeostasis is not restored under prolonged ER stress. Here, we report that Cab45S, a member of the CREC family, inhibits ER stress-induced apoptosis. Depletion of Cab45S increases inositol-requiring kinase 1 (IRE1) activity, thus producing more spliced forms of X-box-binding protein 1 mRNA at the early stage of stress and leads to phosphorylation of c-Jun N-terminal kinase, which finally induces apoptosis. Furthermore, we find that Cab45S specifically interacts with 78-kDa glucose-regulated protein/immunoglobulin heavy chain binding protein (GRP78/BiP) on its nucleotide-binding domain. Cab45S enhances GRP78/BiP protein level and stabilizes the interaction of GRP78/BiP with IRE1 to inhibit ER stress-induced IRE1 activation and apoptosis. Together, Cab45S, a novel regulator of GRP78/BiP, suppresses ER stress-induced IRE1 activation and apoptosis by binding to and elevating GRP78/BiP, and has a role in the inhibition of ER stress-induced apoptosis.

Taurine improves functional and histological outcomes and reduces inflammation in traumatic brain injury

We investigated the effect of taurine on inflammatory cytokine expression, on astrocyte activity and cerebral edema and functional outcomes, following traumatic brain injury (TBI) in rats. 72 rats were randomly divided into sham, TBI and Taurine groups. Rats subjected to moderate lateral fluid percussion injury were injected intravenously with taurine (200mg/kg) or saline immediately after injury or daily for 7days. Functional outcome was evaluated using Modified Neurological Severity Score (mNSS). Glial fibrillary acidic protein (GFAP) of the brain was measured using immunofluorescence. Concentration of 23 cytokines and chemokines in the injured cortex at 1 and 7days after TBI was assessed by Luminex xMAP technology. The results showed that taurine significantly improved functional recovery except 1day, reduced accumulation of GFAP and water content in the penumbral region at 7days after TBI. Compared with the TBI group, taurine significantly suppressed growth-related oncogene (GRO/KC) and interleukin (IL)-1β levels while elevating the levels of regulated on activation, normal T cell expressed and secreted (RANTES) at 1day. And taurine markedly decreased the level of 17 cytokine: eotaxin, Granulocyte colony-stimulating factor (G-CSF), Granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, IL-17, leptin, monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), and only increased the level of MIP-1α in a week. The results suggest that taurine effectively mitigates the severity of brain damage in TBI by attenuating the increase of astrocyte activity and edema as well as pro-inflammatory cytokines.

Population Structures of 'Candidatus Liberibacter asiaticus' in Southern China

Huanglongbing (HLB) is a highly detrimental citrus disease associated with 'Candidatus Liberibacter asiaticus', a nonculturable alpha-proteobacterium. Characterization of the bacterial populations is important for development of disease management strategies. In this study, the 'Ca. L. asiaticus' populations in eight provinces in southern China where HLB is endemic were analyzed based on tandem repeat number (TRN) variations in a previously characterized genomic locus CLIBASIA_01645. Of the 224 HLB samples collected, 175 (78.3%) samples yielded single polymerase chain reaction (PCR) amplicons (the single amplicon group, SAG) and 49 (21.7%) samples produced multiple PCR amplicons (the multiple amplicon group, MAG). Variations in SAG are summarized by Nei's diversity index (H) and ratio of TRN ≤ 10/TRN > 10 genotypes (R10). Variations in the MAG are described by the percentage of occurrence (PMAG). At an orchard-level comparison, the 'Ca. L. asiaticus' population from a Guangdong orchard (n = 24) showed H = 0.50, R10 = 23, and PMAG = 0, significantly different from that of the non-Guangdong orchards in Yunnan (n = 23), H = 0.83, R10 = 2.3, and PMAG = 11.5, and in Hainan (n = 35), H = 0.88, R10 = 1.5, and PMAG = 16.7. In a region-level consideration, the Guangdong 'Ca. L. asiaticus' population (n = 78) was H = 0.77, R10 = 25, and PMAG = 1.3, whereas the non-Guangdong population (n = 84) was H = 0.91, R10 = 1.6, and PMAG = 26.9. Overall, significant differences were observed between the 'Ca. L. asiaticus' population from Guangdong Province and those from the other provinces. A strong aggregation of TRN = 6, 7, and 8 genotypes is characteristic to the 'Ca. L. asiaticus' population in Guangdong. Referenced to genome annotation, we propose that rearrangement of tandem repeats at locus CLIBASIA_01645 could be associated with bacterial environmental adaptation.

Atorvastatin overcomes gefitinib resistance in KRAS mutant human non-small cell lung carcinoma cells

The exact influence of statins on gefitinib resistance in human non-small cell lung cancer (NSCLC) cells with KRAS mutation alone or KRAS/PIK3CA and KRAS/PTEN comutations remains unclear. This work found that transfection of mutant KRAS plasmids significantly suppressed the gefitinib cytotoxicity in Calu3 cells (wild-type KRAS). Gefitinib disrupted the Kras/PI3K and Kras/Raf complexes in Calu3 cells, whereas not in Calu3 KRAS mutant cells. These trends were corresponding to the expression of pAKT and pERK in gefitinib treatment. Atorvastatin (1 μM) plus gefitinib treatment inhibited proliferation, promoted cell apoptosis, and reduced the AKT activity in KRAS mutant NSCLC cells compared with gefitinib alone. Atorvastatin (5 μM) further enhanced the gefitinib cytotoxicity through concomitant inhibition of AKT and ERK activity. Atorvastatin could interrupt Kras/PI3K and Kras/Raf complexes, leading to suppression of AKT and ERK activity. Similar results were also obtained in comutant KRAS/PTEN or KRAS/PIK3CA NSCLC cells. Furthermore, mevalonate administration reversed the effects of atorvastatin on the Kras/Raf and Kras/PI3K complexes, as well as AKT and ERK activity in both A549 and Calu1 cells. The in vivo results were similar to those obtained in vitro. Therefore, mutant KRAS-mediated gefitinib insensitivity is mainly derived from failure to disrupt the Kras/Raf and Kras/PI3K complexes in KRAS mutant NSCLC cells. Atorvastatin overcomes gefitinib resistance in KRAS mutant NSCLC cells irrespective of PIK3CA and PTEN statuses through inhibition of HMG-CoA reductase-dependent disruption of the Kras/Raf and Kras/PI3K complexes.

Effects of pulsed Nd:YAG laser on tensile bond strength and caries resistance of human enamel

This study aims to evaluate the effects of pulsed Nd:YAG laser on the tensile bond strength (TBS) of resin to human enamel and caries resistance of human enamel. A total of 201 human premolars were used in this in vitro study. A flat enamel surface greater than 4 × 4 mm in area was prepared on each specimen using a low-speed cutting machine under a water coolant. Twenty-one specimens were divided into seven groups for morphology observations with no treatment, 35% phosphoric acid etching (30 seconds), and laser irradiation (30 seconds) of pulsed Nd:YAG laser with five different laser-parameter combinations. Another 100 specimens were used for TBS testing. They were embedded in self-cured acrylic resin and randomly divided into 10 groups. After enamel surface pretreatments according to the group design, resin was applied. The TBS values were tested using a universal testing machine. The other 80 specimens were randomly divided into eight groups for acid resistance evaluation. Scanning electron microscope (SEM) results showed that the enamel surfaces treated with 1.5 W/20 Hz and 2.0 W/20 Hz showed more etching-like appearance than those with other laser-parameter combinations. The laser-parameter combinations of 1.5 W/15 Hz and 1.5 W/20 Hz were found to be efficient for the TBS test. The mean TBS value of 14.45 ± 1.67 MPa in the laser irradiated group was significantly higher than that in the untreated group (3.48 ± 0.35 MPa) but lower than that in the 35% phosphoric acid group (21.50 ± 3.02 MPa). The highest mean TBS value of 26.64 ± 5.22 MPa was identified in the combination group (laser irradiation and then acid etching). Acid resistance evaluation showed that the pulsed Nd:YAG laser was efficient in preventing enamel demineralization. The SEM results of the fractured enamel surfaces, resin/enamel interfaces, and demineralization depths were consistent with those of the TBS test and the acid resistance evaluation. Pulsed Nd:YAG laser as an enamel surface pretreatment method presents a potential clinical application, especially for the caries-susceptible population or individuals with recently bleached teeth.

Identification of novel caspase/autophagy-related gene switch to cell fate decisions in breast cancers

OBJECTIVES

Caspases, a family of cysteine proteases with unique substrate specificities, contribute to apoptosis, whereas autophagy-related genes (ATGs) regulate cytoprotective autophagy or autophagic cell death in cancer. Accumulating evidence has recently revealed underlying mechanisms of apoptosis and autophagy; however, their intricate relationships still remain to be clarified. Identification of caspase/ATG switches between apoptosis and autophagy may address this problem.

MATERIALS AND METHODS

Identification of caspase/ATG switches was carried out using a series of elegant systems biology & bioinformatics approaches, such as network construction, hub protein identification, microarray analyses, targeted microRNA prediction and molecular docking.

RESULTS

We computationally constructed the global human network from several online databases and further modified it into the basic caspase/ATG network. On the basis of apoptotic or autophagic gene differential expressions, we identified three molecular switches [including androgen receptor, serine/threonine-protein kinase PAK-1 (PAK-1) and mitogen-activated protein kinase-3 (MAPK-3)] between certain caspases and ATGs in human breast carcinoma MCF-7 cells. Subsequently, we identified microRNAs (miRNAs) able to target androgen receptor, PAK-1 and MAPK-3, respectively. Ultimately, we screened a range of small molecule compounds from DrugBank, able to target the three above-mentioned molecular switches in breast cancer cells.

CONCLUSIONS

We have systematically identified novel caspase/ATG switches involved in miRNA regulation, and predicted targeted anti-cancer drugs. These findings may uncover intricate relationships between apoptosis and autophagy and thus provide further new clues towards possible cancer drug discovery.

Identification of microRNA-regulated autophagic pathways in plant lectin-induced cancer cell death

OBJECTIVES

Plant lectins, carbohydrate-binding proteins of non-immune origin, have recently been reported to induce programmed cell death (including apoptosis and autophagy) in many types of cancer cells. MicroRNAs (miRNAs), small, non-coding endogenous RNAs, ~22 nucleotides (nt) in length, have been well characterized to play essential roles in regulation of the autophagy process in cancer; however, how these miRNAs regulate autophagic pathways in plant lectin-induced cancer cells, still remains an enigma.

MATERIALS AND METHODS

Identification of microRNA-regulated autophagic pathways was carried out using a series of elegant systems - biology and bioinformatics approaches, such as network construction, hub protein identification, targeted microRNA prediction, microarray analyses and molecular docking.

RESULTS

We computationally constructed the human autophagic protein-protein interaction (PPI) network, and further modified this network into a plant lectin-induced network. Subsequently, we identified 9 autophagic hub proteins and 13 relevant oncogenic and tumour suppressive miRNAs, that could regulate these aforementioned targeted autophagic hub proteins, in human breast carcinoma MCF-7 cells. In addition, we confirmed that plant lectins could block the sugar-containing receptor EGFR-mediated survival pathways, involved in autophagic hub proteins and relevant miRNAs, thereby ultimately culminating in autophagic cell death.

CONCLUSIONS

These results demonstrate that network-based identification of microRNAs modulate autophagic pathways in plant lectin-treated cancer cells, which may shed new light on the discovery of plant lectins as potent autophagic inducers, for cancer drug discovery.

Caspase-mediated programmed cell death pathways as potential therapeutic targets in cancer

The caspase family is well characterized as playing a crucial role in modulation of programmed cell death (PCD), which is a genetically regulated, evolutionarily conserved process with numerous links to many human diseases, most notably cancer. In this review, we focus on summarizing the intricate relationships between some members of the caspase family and their key apoptotic mediators, involving tumour necrosis factor receptors, the Bcl-2 family, cytochrome c, Apaf-1 and IAPs in cancer initiation and progression. We elucidate new emerging types of cross-talk between several caspases and autophagy-related genes (Atgs) in cancer. Moreover, we focus on presenting several PCD-modulating agents that may target caspases-3, -8 and -9, and their substrates PARP-1 and Beclin-1, which may help us harness caspase-modulated PCD pathways for future drug discovery.

First-degree relatives of patients with early-onset gastric carcinoma show even at young ages a high prevalence of advanced OLGA/OLGIM stages and dysplasia

BACKGROUND

First-degree relatives (FDRs) of early-onset gastric carcinoma (EOGC) patients are at increased risk of cancer development. OLGA/OLGIM (Operative Link on Gastritis/Intestinal Metaplasia Assessment) classifications have been proposed for the identification of individuals at high risk of gastric cancer development.

AIM

To estimate the prevalence and severity of premalignant conditions and lesions in FDRs of EOGC patients.

METHODS

A case-control study was conducted encompassing 103 FDRs of EOGC patients (cases) and 101 age- and gender-matched controls, all submitted to upper GI endoscopy and OLGA and OLGIM used for staging as well as modified versions with exclusion of the biopsies from incisura angularis in the analysis.

RESULTS

Helicobacter pylori infection was present in 82% of cases (P = 0.001). Atrophy was present in 70% of cases (OLGA stages I-IV). High-risk stages (III-IV) were identified only in cases (19%) (P < 0.001). Dysplasia was diagnosed only in cases (n = 7, P = 0.007). The application of OLGIM, modified OLGA and modified OLGIM classifications led to downgrade of stages in comparison with the original OLGA classification (27%, 15% and 30% respectively). In all classification systems, dysplastic lesions clustered (86%) in high-risk stages.

CONCLUSIONS

FDRs of EOGC patients have, even at young ages, a high prevalence of H. pylori infection, high-risk OLGA and OLGIM stages and dysplasia. These patients should undergo accurate endoscopic observation with at least four biopsies in antrum and corpus to allow adequate staging and follow-up of premalignant conditions and lesions scored in high-risk stages, in accordance with international guidelines recently proposed.

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS): a new autosomal dominant syndrome

OBJECTIVE

The purpose of this study was the clinical and pathological characterisation of a new autosomal dominant gastric polyposis syndrome, gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS).

METHODS

Case series were examined, documenting GAPPS in three families from Australia, the USA and Canada. The affected families were identified through referral to centralised clinical genetics centres.

RESULTS

The report identifies the clinical and pathological features of this syndrome, including the predominant dysplastic fundic gland polyp histology, the exclusive involvement of the gastric body and fundus, the apparent inverse association with current Helicobacter pylori infection and the autosomal dominant mode of inheritance.

CONCLUSIONS

GAPPS is a unique gastric polyposis syndrome with a significant risk of gastric adenocarcinoma. It is characterised by the autosomal dominant transmission of fundic gland polyposis, including areas of dysplasia or intestinal-type gastric adenocarcinoma, restricted to the proximal stomach, and with no evidence of colorectal or duodenal polyposis or other heritable gastrointestinal cancer syndromes.

Helium ion microscopy for high-resolution visualization of the articular cartilage collagen network

The articular cartilage collagen network is an important research focus because network disruption results in cartilage degeneration and patient disability. The recently introduced helium ion microscope (HIM), with its smaller probe size, longer depth of field and charge neutralization, has the potential to overcome the inherent limitations of electron microscopy for visualization of collagen network features, particularly at the nanoscale. In this study, we evaluated the capabilities of the helium ion microscope for high-resolution visualization of the articular cartilage collagen network. Images of rabbit knee cartilage were acquired with a helium ion microscope; comparison images were acquired with a field emission scanning electron microscope (FE-SEM) and a transmission electron microscope (TEM). Sharpness of example high-resolution helium ion microscope and field emission scanning electron microscope images was quantified using the 25-75% rise distance metric. The helium ion microscope was able to acquire high-resolution images with unprecedented clarity, with greater sharpness and three-dimensional-like detail of nanoscale fibril morphologies and fibril connections, in samples without conductive coatings. These nanoscale features could not be resolved by field emission scanning electron microscopy, and three-dimensional network structure could not be visualized with transmission electron microscopy. The nanoscale three-dimensional-like visualization capabilities of the helium ion microscope will enable new avenues of investigation in cartilage collagen network research.

Are current definitions of sarcopenia applicable for older Chinese adults?

This study aims to explore whether the current definitions of sarcopenia are applicable to the older Chinese population. Participants were 783 Chinese adults recruited from four regions in Mainland China: Jinan, Guangzhou, Xi'an, and Chengdu. Body composition was measured by dual energy x-ray absorptiometry. Handgrip strength, body weight, and height were measured by trained technicians, and demographic data were collected through questionnaires. Relative appendicular skeletal muscle, skeletal muscle index (SMI=100 × skeletal muscle mass/ body mass) and residuals methods were applied to identify sarcopenia. Compared with young adults, no significant decrease was found in the relative appendicular skeletal muscle (ASM/height2) in older adults. If the criterion of two standard deviations below the mean value of ASM/height2 in young adults is used, none of older adults in this study could be diagnosed with sarcopenia. In addition, compared with the ASM/height2 and residuals methods, SMI shows higher discriminating power in the identifying persons with low handgrip strength. The data suggest that ASM/height2 method may not be appropriate for diagnosis of sarcopenia in Chinese population. However, whether SMI is a better choice remains inconclusive. Prospective studies are needed to clearly define sarcopenia in Chinese population.

Photonic generation of triangular waveform signals by using a dual-parallel Mach-Zehnder modulator

A photonic approach to generate triangular waveform signals is proposed and analyzed. With active bias control, two sub-MZMs (MZ-a and MZ-b) of a dual-parallel Mach-Zehnder modulator (DP-MZM) operate at minimum transmission point, leaving the main MZM (MZ-c) at quadrature transmission point. Triangular waveform can be observed by a parameter setting of modulation index. The proposal is first analyzed and then validated by simulation. The key significance of the scheme is that it is capable of generating triangular waveform signals via a sinusoid local oscillator.

Chinese parents' perceptions of their children's weights and their relationship to parenting behaviours

PURPOSE

The purpose of this study is to examine Chinese parents' perceptions of their children's weights and explore the parenting behaviours associated with these perceptions.

METHODS

A total of 2143 adolescents and 1869 parents were recruited from secondary schools in Ganzhou and Shantou in China. The adolescents' actual weights and heights were measured by trained testers. The self-reported parents' weights and heights, parental perception of the adolescents' weights, adolescents' perception of their own weights, parenting behaviours and demographic information were collected through the questionnaires distributed to the respondents.

RESULTS

The results based on Kappa statistics show only a slight agreement between parental perception of their children's weights and the adolescents' actual weights (Kappa = 0.221). The results from the logistic regression show that the parents' gender [odds ratio (OR) = 0.80, 95% confidence interval (CI): 0.64-1.00], adolescents' gender (OR = 1.61, 95% CI: 1.29-2.01) and perception of their own weights (OR = 0.30, 95% CI: 0.24-0.38) are associated with the parents' perception of their children's weights. Statistically significant difference in several parenting behaviours was found between the parents with correct and incorrect perceptions of their children's weight.

DISCUSSION AND CONCLUSION

Misconceptions about their children's weights are prevalent among Chinese parents. The association between parents' perception of their children's weight and parenting behaviours suggests that the accurate classification of children's weights could help prevent childhood obesity.

Infection of immunocompromised patients by avian H9N2 influenza A virus

Avian influenza A (H9N2) virus is transmitted sporadically from avian species to human causing mild diseases in immunocompetent person. We report two cases of human infection in immunocompromised patients in Hong Kong between 2008 and 2009. One patient had uneventful recovery with viral shedding at day 10 after symptom onset despite her underlying acute lymphoblastic leukaemia. The other patient with post-bone marrow transplant chronic graft-versus-host disease and bronhioltis obliterans went into respiratory failure. Genetic analysis revealed that these cases were caused by different genetic variants which are circulating in poultry in this region. Review of literature identified another 9 human cases reported in Southern China since 1988. It is possible that human infection with H9N2 is more common than what has been recognized. Continuous surveillance of H9N2 influenza virus infection in human is warranted.

Excess fluoride interferes with chloride-channel-dependent endocytosis in ameloblasts

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF). Both CF and dental fluorosis result in protein retention in mature enamel. We hypothesized that excess fluoride might cause protein retention by interfering with CFTR function, resulting in abnormal expression of proteases and pathological endocytosis. Millimolar concentrations of fluoride reduced uptake of Emdogain, an enamel matrix derivative, in ameloblast-like PABSo-E cells, while stimulating an acidic intracellular environment at the same time. When CFTR function was inhibited by either an siRNA or a chloride channel inhibitor, CFTRinh-172, fluoride's effect on Emdogain uptake was partially blocked. Treatment of cells with CFTR siRNA down-regulated expression of proteases MMP20 and KLK4 and increased intracellular pH. We conclude that excess fluoride inhibits endocytic activity of ameloblasts through the CFTR chloride channel or other chloride channels. The intracellular pH might be the key mechanism by which abnormal proteolytic activity and defective endocytosis cause the residual protein observed in enamel of patients with CF and dental fluorosis.

Is antiepileptic drug use related to depression and suicidal ideation among patients with epilepsy?

Depression and suicide are increased in patients with epilepsy. The U.S. Food and Drug Administration warns that antiepileptic drugs (AEDs) are associated with increased risk of suicidality. This study examines the relationship among depression, suicidal ideation, and AEDs in a prospective cohort of 163 patients with epilepsy from a registry at the University of Florida (January 2006 to August 2008). The Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) was used to measure mood and suicidal ideation across two time points (median = 154 days). Groups included: (1) No AED Change, (2) New AED Added, (3) AED Dose Increased, (4) AED Reduced/Stopped, (5) Multiple AED Changes, and (6) Combined Any AED Change (groups 2-5 combined). No group had worsening mood or suicidal ideation. Significant improvements in proportions of depression and suicidal ideation were seen only for the No AED Change group, which differed only with the AED Dose Increased group with respect to suicidal ideation.

Effect of citrus juice and SLCO2B1 genotype on the pharmacokinetics of montelukast

Previously the authors found that a common polymorphism, rs12422149 (SLCO2B1{NM_007256.2}:c.935G>A), in the gene coding for OATP2B1, was associated with absorption of and response to montelukast in humans. In vitro studies showed that citrus juice could reduce the permeability of montelukast consistent with known inhibition of organic anion-transporting polypeptides. To study the clinical significance of c.935G>A, the authors conducted a single-dose, pharmacokinetic study of montelukast co-ingested with citrus juice. On average, co-ingestion with either orange juice or 4× concentrated grapefruit juice had a minimal effect on the area under the plasma concentration-time curve from time zero extrapolated to infinite time (AUC(0→∞)) of montelukast relative to co-ingestion with Gatorade control (n = 24). However when the data were stratified by genotype at c.935 (G/G n = 21, A/G n = 5), a significant reduction in AUC(0→∞) was detected with orange juice in G/G homozygotes (AUC(0→∞), G/G, Gatorade = 2560 ± 900 ng·h·mL(-1) vs AUC(0→∞), G/G, orange juice = 2010 ± 650 ng·h·mL(-1), P = .032). Significantly, A/G heterozygotes showed reduced AUC(0→∞) relative to G/G homozygotes, independent of treatment (AUC(0→∞), G/G, combined treatments = 2310 ± 820 ng·h·mL(-1) vs AUC(0→∞), A/G, combined treatments = 1460 ± 340 ng·h·mL(-1), P = 2.0 × 10(-5)) replicating previous observations.

Serum concentrations of selected endogenous estrogen and estrogen metabolites in pre- and post-menopausal Chinese women with osteoarthritis

The purpose of this study was to investigate whether serum levels of selected endogenous estrogens and their metabolites are involved in the pathogenesis of osteoarthritis in pre- and post-menopausal women with osteoarthritis. Sixty-four patients with osteoarthritis (OA) of the knee, 48 patients with rheumatoid arthritis (RA) of the knee, and 48 healthy women were included in this study. Serum concentrations of estradiol and estrogen metabolites, such as 2- hydroxyestrone, 2-hydroxyestradiol, and 16α-hydroxyestrone, were measured by high performance liquid chromatography-mass spectrometry. Our results show that the serum concentrations of free estradiol and total 2-hydroxyestrone were significantly lower in pre-menopausal women with OA compared to the levels detected in the control groups (RA and healthy women). While serum concentrations of free and total estradiol in post-menopausal women with OA was significantly decreased compared to those of the control groups, the level of total 2-hydroxyestradiol significantly increased in postmenopausal women. Furthermore, the total 2-hydroxyestrone concentration positively correlated with the total estradiol level in pre-menopausal women with OA. In addition, the total 2- hydroxyestradiol level positively correlated with free and total estradiol levels in post-menopausal women with OA. In conclusion, estradiol and estrogen metabolites, including 2-hydroxyestrone and 2-hydroxyestradiol, were found in the sera of pre- and post-menopausal women with OA. Except for free and total estradiol deficiency, a decreased serum level of total 2- hydroxyestrone in pre-menopausal women and an increased total 2-hydroxyestradiol level in post-menopausal women with OA may also correlate with the pathogenesis of female OA.

Bacterial community dynamics in two full-scale wastewater treatment systems with functional stability

AIMS

To characterize the bacterial community dynamics over 1 year in two full-scale wastewater treatment systems operated under constant conditions and exhibiting stable performance.

METHODS AND RESULTS

Functional stability was defined and quantified by the effluent concentration of biological oxygen demand, total nitrogen and ammonia. Community dynamics were investigated using specific PCR followed by terminal restriction fragment length polymorphism (T-RFLP) of the 16S rRNA gene. The T-RFLP results indicated that during the period of functional stability, the bacterial community structures in two full-scale wastewater treatment systems were not stable, and the average change rates every 15 days of the two systems were 22.6 ± 6.9 and 21.6 ± 7.3%, respectively. The corresponding species with dominant T-RFs were determined by clonal sequencing and T-RFLP. Based on Pareto-Lorenz distribution curves, it was observed that only a small number of micro-organisms were numerically dominant in the two systems.

CONCLUSIONS

The results of this study showed that, throughout the period of the study, the bacterial community structure changed significantly in two full-scale wastewater treatment systems despite the stable function.

SIGNIFICANCE AND IMPACT OF THE STUDY

The findings enrich the theory involving the relation between bacterial community dynamics and functional stability in full-scale wastewater treatment plants.