Characterization and emulsifying property of a novel bioemulsifier by Aeribacillus pallidus YM-1

AIMS

  Biosurfactants and bioemulsifiers commonly have the advantages of biodegradability, low toxicity, selectivity and biocompatibility over chemically synthesized surfactants. The goal of the study is to present a novel bioemulsifier with great application potential.

METHODS AND RESULTS

  Aeribacillus pallidus YM-1, isolated from crude oil contaminated soil, was found to produce a novel high molecular bioemulsifier with an emulsification index of 60 ± 1% without remarkable surface tension reduction (45·7 ± 0·1 mN m(-1) ). The number-average molecular weight was determined as 526 369 Da by gel permeation chromatography analysis. Bioemulsifier was subjected to FT-IR and a complex of carbohydrates (41·1%), lipids (47·6%) and proteins (11·3%) was determined.

CONCLUSIONS

  The bioemulsifier of A. pallidus YM-1 was isolated from the glucose-based culture medium and characterized with the help of chemical analytical techniques. The bioemulsifier exhibited a promising emulsifying property for biotechnology application potential in bioremediation and microbial enhanced oil recovery.

SIGNIFICANCE AND IMPACT OF THE STUDY

  This is the first report of the bioemulsifier production by A. pallidus. The potential emulsifying activity of the bioemulsifier in the present study may be explored in various biotechnological and industrial applications.

Poloxamines for deswelling of organ-cultured corneas

BACKGROUND

Poloxamines are amphiphilic tetrofunctional block copolymers composed of four polyoxyethylene-polyoxypropylene arms joined to a central ethylene diamine bridge. Their safe profile allows diverse pharmaceutical and biomedical applications.

AIM

To assess their use for corneal deswelling using a porcine model of organ culture (OC).

METHODS

Five poloxamines (T90R4, T904, T908, T1107 and T1307) were dissolved in a standard commercial OC medium (control) to reach 350 mosm kg(-1). In vitro cytotoxicity was tested using MTT assay on human corneal epithelial and endothelial cell (EC) lines and on primary human corneal fibroblasts. Paired porcine corneas stored in OC for 3 days were assigned for 48 h to a poloxamine medium or to a standard deswelling medium containing 5% dextran T500. Corneal EC density, morphometry, mortality, stromal thickness and transparency were evaluated before and after deswelling. Post-deswelling, EC viability/mortality was determined using a fluorescent live/dead assay.

RESULTS

Besides similar corneal thickness reduction and transparency improvement, T908, T1107 and T1307 decreased EC loss (5.4 ± 1.7% vs. 9.9 ± 2.6% in controls (p < 0.001)) and mortality, improved EC morphometry and reduced endothelial lesions compared to dextran.

CONCLUSION

On this porcine model, poloxamines T908, T1107 and T1307 appear as good candidates to replace dextran for the deswelling. Experiments on human corneas are now necessary to confirm their efficiency and safety profile in OC.

Targeting microRNA-30a-mediated autophagy enhances imatinib activity against human chronic myeloid leukemia cells

A major advancement in the treatment of chronic myeloid leukemia (CML) has been the development of imatinib and other BCR-ABL tyrosine kinase inhibitors. MicroRNAs (miRNAs) are small RNA molecules that influence gene expression by post-transcriptional regulation of messenger RNA. It is not yet clear how miRNAs are able to regulate the effectiveness of imatinib in CML. Here, we show that imatinib markedly inhibits expression of miR-30a in human CML cells. miR-30a is a potent inhibitor of autophagy by downregulating Beclin 1 and ATG5 expression. miR-30a mimic or knockdown of autophagy genes (ATGs) such as Beclin 1 and ATG5 by short hairpin RNA enhances imatinib-induced cytotoxicity and promotes mitochondria-dependent intrinsic apoptosis. In contrast, knockdown of miR-30a by antagomir-30a increases the expression of Beclin 1 and ATG5, and inhibits imatinib-induced cytotoxicity. These findings indicate that dysregulation of miR-30a may interfere with the effectiveness of imatinib-mediated apoptosis by an autophagy-dependent pathway, thus representing a novel potential therapeutic target in CML.

Demethylation of the FCER1G promoter leads to FcεRI overexpression on monocytes of patients with atopic dermatitis

BACKGROUND

Overexpression of the high-affinity receptor for immunoglobulin E on atopic monocytes and dendritic cells is known to contribute to the pathogenesis of atopic dermatitis (AD). However, it remains unclear what is the underlying mechanism of FcεRI deregulation. It has been speculated that epigenetic deregulation may play a role.

METHODS

Global DNA methylation levels of monocytes from 10 AD patients and 10 healthy controls were measured using a global DNA methylation kit. Bisulfite sequencing was performed to determine the methylation status of the FCER1G promoter region. FcεRIγ mRNA and FcεRI protein levels were detected by real-time RT-PCR, Western blotting, and flow cytometry, respectively. Patch methylation and the demethylating agent, 5-azacytidine, were used to determine the functional significance of methylation changes on FcεRI expression.

RESULTS

Monocytes from AD patients show a global hypomethylation, as well as a locus-specific hypomethylation at FCER1G promoter, as compared to healthy controls. Furthermore, this hypomethylation of FCER1G is inversely correlated with its expression. Patch methylation in combination with luciferase reporter assay confirmed the direct relationship between methylation and expression. Moreover, treating healthy monocytes with 5-azacytidine caused a reduction in methylation levels and an induction in FcεRIγ transcription and surface expression of FcεRI.

CONCLUSION

Demethylation of specific regulatory elements within the FCER1G locus contributes to FcεRI overexpression on monocytes from patients with AD.

Abnormal epigenetic modifications in peripheral blood mononuclear cells from patients with alopecia areata

BACKGROUND

Alopecia areata (AA) is a hair loss disease caused by T-cell-mediated autoimmune reactions against anagen-stage hair follicles. Although the exact aetiology is poorly understood, there is evidence to suggest that both genetic and environmental factors are involved in AA pathogenesis.

OBJECTIVES

To analyse DNA methylation and histone modification patterns in peripheral blood mononuclear cells (PBMCs) of patients with AA.

METHODS

PBMC samples were obtained from 25 patients with AA and 20 healthy controls. Global DNA methylcytosine levels, as well as histone acetylation and methylation levels, were measured by enzyme-linked immunosorbent assay. mRNA expression levels were determined using real-time quantitative reverse transcription-polymerase chain reaction.

RESULTS

Genomic DNA methylation in PBMCs of patients with AA was increased relative to controls. DNMT1, MBD1 and MBD4 expression levels were significantly higher in AA PBMCs than in controls, and DNMT1 transcription levels positively correlated with global DNA methylation levels in patient samples. Histone H3 acetylation was significantly increased and histone H3 lysine 4 methylation was significantly decreased in patient PBMCs compared with healthy controls. Histone H3 acetylation levels were positively correlated with AA disease severity, and with RANTES (CCL5) mRNA expression in PBMCs of patients with AA. These changes were accompanied by increased p300 (EP300), histone deacetylase 1 (HDAC1), myeloid/lymphoid or mixed lineage leukemia (MLL), SET7/9 (SETD7), G9A (EHMT2), JMJD2C (KDM4C) and JARID1A (KDM5A) expression, as well as reduced HDAC2, HDAC7, LSD1 (KDM1A), JMJD2A (KDM4A) and JMJD2B (KDM4B) expression.

CONCLUSIONS

DNA methylation and histone modification status are altered in PBMCs of patients with AA, possibly due to the deregulation of epigenetic regulatory genes. These changes may contribute to the activation of pathological immune responses in AA.

Aggressive angiomyxoma of the vulva: intra-operative pathological diagnosis is useful in deciding the scope of surgery and reducing recurrence

Aggressive angiomyxoma (AA) is a rare, slow-growing myxoid neoplasm of the pelvi-perineum. Because of its rarity, it is often initially misdiagnosed, frequently as a gynaecological malignancy. Surgical resection is the main treatment modality of AA, but, local recurrence rates are high. In order to reduce recurrence, the scope of surgical resection should be as broad as possible. Intra-operative pathological diagnosis is useful in deciding the scope of surgery, and wide excision may reduce recurrence.

Hepatitis C among methadone maintenance treatment patients in Shanghai and Kunming, China

BACKGROUND

This study aims to: (1) document the prevalence of hepatitis C virus (HCV) among methadone maintenance treatment (MMT) patients in Kunming and Shanghai; (2) examine risk factors for HCV by comparing those who tested positive with those who were negative and (3) examine if HCV serostatus is related to attitudes toward MMT.

METHODS

Using data collected from 306 patients admitted to MMT in 2009-2010 in Shanghai and Kunming, we compared HCV-positive and HCV-negative patients (based on clinical records) on their HCV knowledge and risk behaviors and attitudes toward MMT.

RESULTS

The HCV seropositive rate was 53.3% (51.3% in Shanghai and 55.5% in Kunming) and a majority of patients did not know their serostatus. Patients scored on average fewer than 6 correct out of the 20 items in the HCV knowledge questionnaire. Recent injection use and length of opiate use were strong predictors of HCV status, while no differences were found between HCV-positive and HCV-negative individuals in sexual risks or HCV knowledge. Both groups expressed similar views toward MMT.

CONCLUSION

The high HCV prevalence and the general lack of knowledge about HCV infection, transmission and treatment suggest the need to provide HCV education and health promotion programs among patients in MMT.

Azilsartan treatment improves insulin sensitivity in obese spontaneously hypertensive Koletsky rats

AIM

Hypertension often coexists with insulin resistance. However, most metabolic effects of the antihypertensive agents have been investigated in nomotensive animals, in which different conclusions may arise. We investigated the metabolic effects of the new angiotensin II type 1 receptor blocker azilsartan using the obese Koletsky rats superimposed on the background of the spontaneously hypertensive rats.

METHODS

Male Koletsky rats were treated with azilsartan (2 mg/kg/day) over 3 weeks. Blood pressure was measured by tail-cuff. Blood biochemical and hormonal parameters were determined by enzymatic or ELISA methods. Gene expression was assessed by RT-PCR.

RESULTS

In Koletsky rats, azilsartan treatment lowered blood pressure, basal plasma insulin concentration and the homeostasis model assessment of insulin resistance index, and inhibited over-increase of plasma glucose and insulin concentrations during oral glucose tolerance test. These effects were accompanied by decreases in both food intake and body weight (BW) increase. Although two treatments showed the same effect on BW gain, insulin sensitivity was higher after azilsartan treatment than pair-feeding. Azilsartan neither affected plasma concentrations of triglyceride and free fatty acids, nor increased adipose mRNA levels of peroxisome proliferator-activated receptor (PPAR)γ and its target genes such as adiponectin, aP2. In addition, azilsartan downregulated 11β-hydroxysteroid dehydrogenase type 1 expression.

CONCLUSIONS

These results show the insulin-sensitizing effect of azilsartan in obese Koletsky rats. This effect is independent of decreases in food intake and BW increase or of the activation of adipose PPARγ. Our findings indicate the possible usefulness of azilsartan in the treatment of metabolic syndrome.

Phase I study of the histone deacetylase inhibitor entinostat in combination with 13-cis retinoic acid in patients with solid tumours

BACKGROUND

Preclinical studies suggest that histone deacetylase (HDAC) inhibitors may restore tumour sensitivity to retinoids. The objective of this study was to determine the safety, tolerability, and the pharmacokinetic (PK)/pharmacodynamic (PD) profiles of the HDAC inhibitor entinostat in combination with 13-cis retinoic acid (CRA) in patients with solid tumours.

METHODS

Patients with advanced solid tumours were treated with entinostat orally once weekly and with CRA orally twice daily × 3 weeks every 4 weeks. The starting dose for entinostat was 4 mg m(-2) with a fixed dose of CRA at 1 mg kg(-1) per day. Entinostat dose was escalated by 1 mg m(-2) increments. Pharmacokinetic concentrations of entinostat and CRA were determined by LC/MS/MS. Western blot analysis of peripheral blood mononuclear cells and tumour samples were performed to evaluate target inhibition.

RESULTS

A total of 19 patients were enroled. The maximum tolerated dose (MTD) was exceeded at the entinostat 5 mg m(-2) dose level (G3 hyponatremia, neutropenia, and anaemia). Fatigue (G1 or G2) was a common side effect. Entinostat exhibited substantial variability in clearance (147%) and exposure. CRA trough concentrations were consistent with prior reports. No objective responses were observed, however, prolonged stable disease occurred in patients with prostate, pancreatic, and kidney cancer. Data further showed increased tumour histone acetylation and decreased phosphorylated ERK protein expression.

CONCLUSION

The combination of entinostat with CRA was reasonably well tolerated. The recommended phase II doses are entinostat 4 mg m(-2) once weekly and CRA 1 mg kg(-1) per day. Although no tumour responses were seen, further evaluation of this combination is warranted.

Versatile computer-controlled system for characterization of gas sensing materials

Design of a system used for characterizing gas sensing materials is described. It is distinctive of being able to measure electrical and optical responses of a sample simultaneously, control a number of measurement parameters, perform fast exchange of gaseous environment, and be fully controlled automatically. These features make the system to be versatile in determining most concerned performance indexes of a gas sensing material (e.g., sensitivity, stability, selectivity, response/recovery times, etc.) as functions of various combinations of measurement conditions (e.g., gas concentrations, temperature, total pressure, content of interferants, photo assist, relative humidity, soaking time in a fixed gas concentration, and number of switching cycles in a dynamic test, etc.). Rationales of the designs associated with general gas sensing mechanics are discussed.

Genetic comparisons between seed bank and Stipa krylovii plant populations

The soil seed bank represents the potential plant population since it is the source for population replacement. The genetic structure of a Stipa krylovii (Roshev.) plant population and its soil seed bank was investigated in the Xilinguole Steppe of Inner Mongolia using random amplified polymorphic DNA (RAPD) analyses. The population was sampled at two sites that were in close proximity to each other (0.5 km apart). Thirty plants and 18 seed bank samples were taken from each site to determine the genetic diversity between sites and between sources (plant or seed). The material was analyzed using 13 primers to produce 92 loci. Eighty-six were multi-loci, of which 23 loci (26.74%) of allele frequencies showed significant differences (P < or = 0.05). The genetic similarity between two seed bank sites was 0.9843 while the genetic similarity between two plant sites was 0.9619. Their similarities were all greater than that between the seed bank and plant populations. An analysis of their genetic structure showed that 87.86% of total variation was derived by two-loci. Genetic structures between plant and soil seed bank populations in S. krylovii were different due to the variance of mean gametic disequilibria and mean gene diversity. AMOVA results showed that the majority of variance (88.62%) occurred within sites, 12.75% was from between-groups. Further research is needed to investigate the selective function in maintaining the genetic diversity of Stipa krylovii plant populations.

Histone modifications and methyl-CpG-binding domain protein levels at the TNFSF7 (CD70) promoter in SLE CD4+ T cells

Abstract: In systemic lupus erythematosus (SLE), T lymphocytes overexpress CD70 ( TNFSF7 gene), leading to the synthesis of autoreactive IgGs. CD70 upregulation in SLE CD4+ T cells is associated with hypomethylation of TNFSF7 promoter. In this study, we explored histone modifications in the TNFSF7 promoter region in SLE CD4+ T cells, and characterized the effects of a DNA methyltransferase inhibitor (5-azaC) and a histone deacetylase inhibitor (TSA) on CD70 expression. We found that CD70 mRNA was significantly increased in active lupus CD4+ T cells, and in control cells treated with 5-azaC, TSA, or both. Histone H3 acetylation and dimethylated H3 lysine 4 (H3K4me2) levels were significantly elevated in patients with lupus, and both factors correlated positively with disease activity. MeCP2 protein levels within the TNFSF7 promoter decreased in patients with active lupus. Treatment of CD4+ T cells with 5-azaC alone significantly raised H3K4 dimethyl levels at the TNFSF7 locus. TSA treatment significantly increased H3 and H4 acetylation levels, as well as levels of H3K4 dimethylation at the TNFSF7 locus. Treatment with 5-azaC plus TSA enhanced H3 acetylation levels. These findings indicate that aberrant histone modifications within the TNFSF7 promoter may contribute to the development of lupus by increasing CD70 expression in CD4+ T cells.

In vivo evaluation of quantitative MR angiography in a canine carotid artery stenosis model

BACKGROUND AND PURPOSE

Large-vessel cerebral blood flow quantification has emerged as a potential predictor of stroke risk. QMRA uses phase-contrast techniques to noninvasively measure vessel flows. To evaluate the in vivo accuracy of QMRA for measuring the effects of progressive arterial stenosis, we compared this technique with invasive flow measurements from a sonographic transit-time flow probe in a canine model.

MATERIALS AND METHODS

A sonographic flow probe was implanted around the CCA of hound dogs (n = 4) under general anesthesia. Pulsatile blood flow and arterial pressure were continuously recorded during CCA flow measurements with QMRA. A vascular tourniquet was applied around the CCA to produce progressive stenosis and varying flow rates. Statistical comparisons were made by using the Pearson product moment correlation coefficient.

RESULTS

A total of 60 paired CCA flow measurements were compared. Mean blood flows ranged between 21 and 691 mL/min during QMRA acquisition as measured by the flow probe. The correlation coefficients between flow probe and QMRA measurements for mean, maximum, and minimum volume flow rates were 0.99 (P < .0001), 0.98 (P < .0001), and 0.96 (P < .0001), respectively. The overall proportional difference between the 2 techniques was 7.8 ± 1%. Measurements at higher flow rates and in the absence of arterial stenosis had the lowest PD.

CONCLUSIONS

Noninvasive CCA flow measurements by using QMRA are accurate compared with invasive flow-probe measurements in a canine arterial flow model with stenosis and may be useful for the evaluation of the hemodynamic effects of stenosis caused by cerebrovascular atherosclerosis.

Observation of the decay B- → D(s)((*)+) K- ℓ- ν(ℓ)

We report the observation of the decay B- → D(s)((*)+) K- ℓ- ν(ℓ) based on 342  fb(-1) of data collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e+ e- storage rings at SLAC. A simultaneous fit to three D(s)(+) decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B- → D(s)((*)+) K- ℓ- ν(ℓ) with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B- → D(s)((*)+) K- ℓ- ν(ℓ)) = [6.13(-1.03)(+1.04)(stat)±0.43(syst)±0.51(B(D(s)))]×10(-4), where the last error reflects the limited knowledge of the D(s) branching fractions.

Search for production of invisible final states in single-photon decays of Υ(1S)

We search for single-photon decays of the Υ(1S) resonance, Υ → γ + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A⁰, or a pair of dark matter particles, χχ. Both A⁰ and χ are assumed to have zero spin. We tag Υ(1S) decays with a dipion transition Υ(2S) → π⁺π⁻Υ(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m(A⁰) ≤ 9.2 GeV and m(χ) ≤ 4.5 GeV in the sample of 98 × 10⁶ Υ(2S) decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.