Production of a novel bioflocculant MNXY1 by Klebsiella pneumoniae strain NY1 and application in precipitation of cyanobacteria and municipal wastewater treatment

AIMS

To isolate and characterize the novel bioflocculant-producing bacteria, to optimize the bioflocculant production and to evaluate its potential applications.

METHODS AND RESULTS

Klebsiella pneumoniae strain NY1, a bacterium that produces a novel bioflocculant (MNXY1), was selected on the chemically defined media. It was classified according to the 16S rRNA gene sequence, morphological and microscopic characteristics. MNXY1 was characterized to contain 26% protein and 66% total sugar. The constituent sugar monomers of MNXY1, revealed by NMR analysis, are glucose, galactose and quinovose. Favourable culture conditions for MNXY1 production were determined. Strain NY1 produces a high level (14.9 g l(-1)) of MNXY1. MNXY1 is thermostable and tolerant to the extreme pH. It precipitated 54% of cyanobacteria from laboratory culture and 72% of the total suspended solids from raw wastewater.

CONCLUSIONS

Strain NY1 was identified to produce a novel bioflocculant MNXY1. The outstanding performance of MNXY1 in practical applications and its availability in copious amounts make it attractive for further investigation and development for industrial scale applications.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is first report for the identification of a quinovose-containing bioflocculant and application of a protein-polysaccharide complex bioflocculant in precipitation of cyanobacteria. These findings suggest that MNXY1 holds great potential for use in management of harmful algae and city wastewater treatment.

Clinical and virological characteristics of chronic hepatitis B with concurrent hepatitis B E antigen and antibody detection

The concurrent detection of hepatitis B e antigen (HBeAg) and its corresponding antibody (anti-HBe) in patients with chronic hepatitis B virus (HBV) infection is well established but the clinical features remain poorly understood. Demographic information, clinical and laboratory data were collected from 1624 consecutive inpatient records of patients with chronic hepatitis B. Viral genotype, basic core promoter and precore mutations were determined by direct sequencing. In vitro HBeAg and anti-HBe binding experiments were conducted with three pairs of HBeAg-positive and anti-HBe-positive serum samples, which were mixed at variable ratios and incubated at 37°C for 3-24h. Of the 1624 chronic patients, 169 (10.4%) had concurrent HBeAg and anti-HBe positivity, and this was associated with intermediate age and HBV-DNA load, higher alanine aminotransferase level and more pronounced liver damage compared with HBeAg-positive or anti-HBe-positive patients alone. HBeAg and anti-HBe titres (median and interquartile range, S/CO) in the concurrent positive group were 4.2 (1.8-9.6) and 0.54 (0.27-0.72), which were closer to their respective cut-off values than those of HBeAg-positive or anti-HBe-positive groups alone. For the cases successfully sequenced, 110/134 (82.1%) harboured T1762/A1764 or/and A1896 mutants. The binding experiments showed that HBeAg and anti-HBe could be concurrently observed provided an optimal ratio (HBeAg to anti-HBe) was chosen. In antiviral treatment-naive patients, concurrence of HBeAg and anti-HBe was not uncommon, and such patients had profound liver disease. An optimal ratio between HBeAg and anti-HBe led to their concurrent detection when sera were tested by sensitive assays.

Transcriptional profiling analysis of HMP-treated rats with experimentally induced myocardial infarction

ETHNOPHARMACOLOGICAL RELEVANCE

Heart-protecting musk pill (HMP), a traditional Chinese medicine prescription, has extensive cardioprotective effects against angina pectoris and myocardial infarction (MI), but the molecular mechanism behind such cardio protective effects still remains unclear. In this article, we aim to investigate the effect of HMP on mRNA expression in MI rat.

MATERIALS AND METHODS

A rat model of coronary artery ligation was used to assess the cardioprotective effects of HMP. Microarray technology was applied to detect the gene expression in the heart of MI rats treated with HMP. Besides, quantitative real-time PCR was performed to verify the microarray results.

RESULTS

Our results showed that HMP could ameliorate heart function, and diminish infarct size in MI rats. Compared with sham-operated rats, 500 genes' expression changed, with 234 genes down-regulated and 266 genes up-regulated. And the expression of 129 genes was different between HMP administrated rats and MI rats, with 22 genes down-regulated and 107 genes up-regulated.

CONCLUSIONS

Citrate cycle (TCA cycle), Valine, leucine and isoleucine degradation, Glycolysis/Gluconeogenesis and Pyruvate metabolism pathway are probably involved in the cardioprotective effects of HMP.

Peer relationships and suicide ideation and attempts among Chinese adolescents

BACKGROUND

Suicide is a global health concern. Therefore, studying suicide behaviour and identifying the early roots of suicide are critical. To address these issues, the present study examined (i) the association between peer relationships and suicide ideation and attempts among Chinese adolescents; and (ii) whether such associations were moderated or mediated by feeling of loneliness. We hypothesized that problems in peer relationships were positively associated with suicide ideation and attempts, and that feeling of loneliness would moderate and mediate such associations.

METHODS

The sample included 8778 Chinese adolescents from a large survey. Measures of peer relationships, suicide ideation and attempts, and feeling of loneliness were obtained through adolescents' self-reports.

RESULTS

Results from multivariate logistic regressions suggested that specific problems in peer relationships, such as lack of peer association and being victimized by bullying, were significantly related to suicide ideation and attempts. In addition, the moderating effects of feeling of loneliness on the association between peer relationships and suicide ideation and attempts were found. Finally, some gender effects were also found.

CONCLUSIONS

The present study provided strong evidence that suicide ideation and attempts were serious problems among adolescents in China, to which peer relationships played an important role. Further, feeling of loneliness acted as a moderator affecting the association between peer relationships and suicide ideation and attempts. Finally, there were some gender differences that have important implications.

Fullerenes for applications in biology and medicine

Fullerenes as a unique class of carbon allotropes have been studied extensively for their distinctive material properties and potential technological applications, including those in biology and medicine. Since a major focus in the latter has been on drug development and formulation, in this paper we highlight some representative studies related to such a focus, including the use of fullerenes for drug-like functions and for their improving the formulation of established drugs. Also discussed are some other potential medically relevant applications of fullerenes, such as their serving as potent agents in photodynamic therapy and magnetic imaging.

Clinical pictures and novel mutations of WT1-associated Denys-Drash syndrome in two Chinese children

Denys-Drash syndrome (DDS) is characterized by early onset of nephropathy, genitalia malformation, and Wilms' tumor, where WT1 is the gene that is mutated in most patients. We report two de novo mutations in WT1 found in two Chinese DDS children. Patient 1 was a boy with complete DDS who was presented with progressive nephropathy, unilateral Wilms' tumor, bilateral cryptorchidism, and renal histology showing diffuse mesangial sclerosis (DMS). When the patient was 24 months old, a liver ultrasound showed multiple nodules, and the patient died of pneumonia 1 month later. The de novo novel mutation, c.1130A>T (p.His377Leu), was identified; the mutation replaces histidine with leucine in the zinc finger (Znf) structure and is predicted to change the local spatial structure of the protein. Patient 2 had 46 XX with incomplete DDS and presented with normal genitalia, proteinuria, unilateral Wilms' tumor with renal pedicle lymph node metastasis, and renal histology showing DMS. Her renal function remains normal after 48 months. A de novo mutation, c.1168C>T (p.Arg390Term), was identified; it truncates 60 amino acids at the C terminus, and it is predicted to result in loss of the DNA-binding capacities of the WT1 protein.

Single spin asymmetries in charged pion production from semi-inclusive deep inelastic scattering on a transversely polarized 3He Target at Q2 = 1.4-2.7 GeV2

We report the first measurement of target single spin asymmetries in the semi-inclusive (3)He(e,e'π(±))X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16 < x < 0.35 with 1.4 < Q(2) < 2.7 GeV(2). The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π(±) Collins moments for (3)He are consistent with zero, except for the π(+) moment at x = 0.35, which deviates from zero by 2.3σ. While the π(-) Sivers moments are consistent with zero, the π(+) Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to (3)He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.

Enhanced neurodegeneration after a high dose of methamphetamine in adenosine A3 receptor null mutant mice

Previous reports have indicated that adenosine A3 receptor (A3R) knockout mice are more sensitive to ischemic or hypoxic brain injury. The purpose of this study was to examine if suppression of A3R expression is associated with increase in sensitivity to injury induced by a high dose of methamphetamine (Meth). Adult male A3R null mutant (-/-) mice and their controls (+/+) were injected with four doses (2 h apart) of Meth (10 mg/kg) or saline. Animals were placed in a behavioral activity chamber, equipped with food and water, for 52 h starting from one day after injections. The first 4 h were used for studying exploratory behaviors, and the next 48 h were used to measure locomotor activity. High doses of Meth equally reduced the 4-h exploratory behavior in -/- and +/+ mice. Meth suppressed locomotor activity between 4 and 52 h in both groups, with a greater reduction being found in the -/- mice. Brain tissues were collected at 3 days after the Meth or saline injections. Meth treatment reduced striatal dopamine (DA) levels in both +/+ and -/- mice with an increase in 3,4-dihydroxyphenylacetic acid (DOPAC)/DA ratio being found only in -/- animals. Meth also significantly increased ionized calcium-binding adaptor molecule 1 (Iba-1) and cleaved caspase-3 level in striatum, as well as Iba-1 and TNFα mRNA expression in nigra in -/-, compared to +/+, mice. Previous studies have shown that pharmacological suppression of vesicular monoamine transport 2 (VMAT2) by reserpine enhanced Meth toxicity by increasing cytosolic DA and inflammation. A significant reduction in striatal VMAT2 expression was found in -/- mice compared to +/+ mice, suggesting that increase in sensitivity to Meth injury in -/- mice may be related to a reduction in VMAT2 expression in these mice. In conclusion, our data suggest that A3R -/- mice are more sensitive to high doses of Meth.

Fat emulsion composition alters intake and the effects of baclofen

Thickened oil-in-water emulsions are useful model foods in rat studies due to their high acceptance and similarity to foods consumed by humans. Previous work from this laboratory used oil-in-water emulsions thickened with a biopolymer blend containing starch. Intake and effects of baclofen, a GABA-B agonist that decreases fat intake and drug self-administration, were reported, but the contribution of starch was not assessed. In the present study, intake and effects of baclofen were assessed in rats using emulsions prepared with two fat types (32% vegetable shortening, 32% corn oil) and thickened with three biopolymer blends. One biopolymer blend contained starch and the other two did not. Daily 1-h intake of the vegetable shortening emulsion containing starch was significantly greater than the other emulsions. When starch was added to the emulsions originally containing no starch, intake significantly increased. Baclofen generally reduced intake of all emulsions regardless of starch content and stimulated intake of chow. However, effects were more often significant for vegetable shortening emulsions. This report: (1) demonstrates that products used to prepare thickened oil-in-water emulsions have significant effects on rat ingestive behavior, and (2) confirms the ability of baclofen to reduce consumption of fatty foods, while simultaneously stimulating intake of chow.

A Rac1/PAK1 cascade controls β-catenin activation in colon cancer cells

P21-activated kinase 1 (PAK1) is associated with colon cancer progression and metastasis, whereas the molecular mechanism remains elusive. Here, we show that downregulation of PAK1 in colon cancer cells reduces total β-catenin level, as well as cell proliferation. Mechanistically, PAK1 directly phosphorylates β-catenin proteins at Ser675 site and this leads to more stable and transcriptional active β-catenin. Corroborating these results, PAK1 is required for full Wnt signaling, and superactivation of β-catenin is achieved by simultaneous knockdown of adenomatous polyposis coli protein and activation of PAK1. Moreover, we show that Rac1 functions upstream of PAK1 in colon cancer cells and contributes to β-catenin phosphorylation and accumulation. We conclude that a Rac1/PAK1 cascade controls β-catenin S675 phosphorylation and full activation in colon cancer cells. Supporting this conclusion, overexpression of PAK1 is observed in 70% of colon cancer samples and is correlated with massive β-catenin accumulation.

The expression of histone demethylase JMJD1A in renal cell carcinoma

BACKGROUND

Hypoxia-inducible factor 1α has been shown to play a central role in RCC tumorigenesis by acting as a transcription factor. Histone demethylase JMJD1A is an iron- and 2-oxoglutarate-dependent dioxygenase which catalyze the demethylation of mono- and dimethylated H3K9. JMJD1A can be upregulated by hypoxia via HIF-1 and associated with cancer. The expression of JMJD1A was determined in 10 kidney cancer tissue and adjacent tissue by quantitative polymerase chain reaction, western blotting and immunohistochemistry. Furthermore, the expression of JMJD1A was investigated in cell line 786-0 through adding nickle or cobalt ion to mimic hypoxic environment. The expression of JMJD1A was higher in cancer tissue than adjacent tissue, and in hypoxic environment than normal environment. In cancer tissue, the JMJD1A mainly located around blood vessels which indicated that JMJD1A is involved tumor angiogenesis.

CONCLUSION

the increased expression of JMJD1A might be associated with the progression of kidney cancer.

KEYWORDS

renal cell carcinoma, histone demethylase, JMJD1A, hypoxia-inducible factor, iron.

Innate immunity and HIV-1 infection

HIV-1 is predominantly transmitted through mucosal tissues, targeting CD4(+)CCR5(+) T cells, 50% of which are destroyed within 2 weeks of infection. Conventional vaccination strategies have so far failed to prevent HIV-1 infection. Neither antibodies nor cytotoxic lymphocytes are capable of mounting a sufficiently rapid immune response to prevent early destruction of these cells. However, innate immunity is an early-response system, largely independent of prior encounter with a pathogen. Innate immunity can be classified into cellular, extracellular, and intracellular components, each of which is exemplified in this review by γδ T cells, CC chemokines, and APOBEC3G, respectively. First, γδ T cells are found predominantly in mucosal tissues and produce cytokines, CC chemokines, and antiviral factors. Second, the CC chemokines CCL-3, CCL-4, and CCL-5 can be upregulated by immunization of macaques with SIVgp120 and gag p27, and these can bind and downmodulate CCR5, thereby inhibiting HIV-1 entry into the host cells. Third, APOBEC3G is generated and maintained following rectal mucosal immunization in rhesus macaques for over 17 weeks, and the innate anti-SIV factor is generated by CD4(+)CD95(+)CCR7(-) effector memory T cells. Thus, innate anti-HIV-1 or SIV immunity can be linked with immune memory, mediated by CD4(+) T cells generating APOBEC3G. The multiple innate functions may mount an early anti-HIV-1 response and either prevent viral transmission or contain the virus until an effective adaptive immune response develops.

Effects of ginger root (Zingiber officinale) on laying performance and antioxidant status of laying hens and on dietary oxidation stability

To investigate the effects of ginger root (Zingiber officinale) on laying performance and antioxidant status of laying hens and on dietary oxidation stability, 675 Hy-Line brown laying hens at 27 wk of age were randomly allocated to 5 treatments with 5 replicates in a complete randomized design. Laying hens were fed corn-soybean meal based diets and supplemented with 0, 5, 10, 15, or 20 g of ginger powder/kg of diet for 10 wk. The ADFI, laying rate, average egg weight, egg mass, and feed conversion of each replicate were measured weekly. Blood samples from 10 laying hens and 15 egg samples/treatment were obtained on d 35 and 70 of the experiment to determine the serum or egg yolk antioxidant enzymatic activities. Three separate batches of each treatment diet were also made at the beginning of the experiment and stored at 20°C. Subsamples were taken at 10-d intervals to determine the dietary oxidation stability over a 60-d period. All laying hens had similar ADFI, laying rate, average egg weight, and feed conversion. However, laying hens supplemented with ginger powder had higher (P = 0.024) egg mass than the control group. Supplementation of ginger powder increased (P < 0.05) the serum and egg yolk antioxidant enzymatic activities of laying hens on d 35 and 70. Increasing ginger powder from 0 to 20 g/kg of diet linearly increased (P < 0.05) the peroxide value but linearly reduced (P < 0.05) the acid value of lipid extracted from stored diets for the first 30 d, but not for the second 30 d. Dietary supplementation of ginger powder improved laying performance and serum and egg yolk antioxidant status and enhanced dietary oxidation stability in a dose-dependent manner. The optimum supplementation rate of ginger powder in the diet of laying hens appeared to be between 10 and 15 g/kg of diet.

Abnormalities in connectivity of white-matter tracts in patients with familial and non-familial schizophrenia

BACKGROUND

Abnormalities in the connectivity of white-matter (WM) tracts in schizophrenia are supported by evidence from post-mortem investigations, functional and structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). The aims of this study were to explore the microstructural changes in first-episode schizophrenia in a Han Chinese population and to investigate whether a family history of psychiatric disorder is related to the severity of WM tract integrity abnormalities in these patients.

METHOD

T1-weighted MR and DT images were collected in 68 patients with first-episode schizophrenia [22 with a positive family history (PFH) and 46 with a negative family history (NFH)] and 100 healthy controls. Voxel-based analysis was performed and WM integrity was quantified by fractional anisotropy (FA). Cluster- and voxel-level analyses were performed by using two-sample t tests between patients and controls and/or using a full factorial model with one factor and three levels among the three sample groups (patients with PFH or NFH, and controls), as appropriate.

RESULTS

FA deficits were observed in the patient group, especially in the left temporal lobe and right corpus callosum. This effect was more severe in the non-familial schizophrenia than in the familial schizophrenia subgroup.

CONCLUSIONS

Overall, these findings support the hypothesis that loss of WM integrity may be an important pathophysiological feature of schizophrenia, with particular implications for brain dysmaturation in non-familial and familial schizophrenia.

Cost-saving biological nitrogen removal from strong ammonia landfill leachate

The aim of the study was to develop an improved management mode in Ämmässuo landfill (Finland) for leachate ammonium-nitrogen removal, to minimize the leachate management costs and secure compliance with the uptrend requirements of regulations for on-site leachate management. With a single sequential batch simulation reactor, the minimum C/N ratio was detected as 1.7 (adjusted by external carbon addition), to achieve the acceptable removal efficiency of 99, 62 and 74% in NH( 4)-N, total nitrogen and chemical oxygen demand, respectively. Both total nitrogen removal and efficiency of carbon use were correlated with an increasing NO(-) (2) /NO(-) (x) ratio indicating higher performance with denitrification via nitrite. It was estimated that the leachate management cost could be reduced by 28 to 38%.