Extremely low-frequency electromagnetic field exposure enhances inflammatory response and inhibits effect of antioxidant in RAW 264.7 cells

In recent years, there has been a dramatic increase in the number and variety of electronic devices that emit electromagnetic waves. Because people live and work in close proximity to these pieces of electrical equipment, there is growing concern surrounding the destruction of homeostasis by electromagnetic field exposure. In the present study, the effects of 60 Hz 0.8 mT extremely low-frequency electromagnetic fields (ELF-EMF) on a macrophage cell line (RAW 264.7) were examined. Under defined ELF-EMF exposure conditions, the production of nitric oxide and pro-inflammatory cytokines, TNF-α, IL-1β, and IL-6, were increased in RAW 264.7 cells and the expression of those genes was also upregulated. However, cell proliferation was not altered. Translocation of NF-κB (nuclear factor kappa B), molecules that act downstream of the pro-inflammatory cytokines, were increased to the nucleus under ELF-EMF exposure conditions. In addition, we found that ELF-EMF exposure elevated activation of nuclear factor of activated T cells (NFAT) 2, as well as positively affected the influx of calcium. Furthermore, with both the presence of a potent antioxidant (Resveratrol) and downregulation of the antioxidant-related gene Prx-1 (Peroxiredoxin-1), ELF-EMF was associated with higher inflammatory responses of macrophages. These results suggest that an ELF-EMF amplifies inflammatory responses through enhanced macrophage activation and can decrease the effectiveness of antioxidants. Bioelectromagnetics. 38:374-385, 2017. © 2017 Wiley Periodicals, Inc.

Quantitative determination of a synthetic amide derivative of gallic acid, SG-HQ2, using liquid chromatography tandem mass spectrometry, and its pharmacokinetics in rats

An amide derivative of gallic acid (GA), 3,4,5-trihydroxy-N-(8-hydroxyquinolin-2-yl)benzamide) (SG-HQ2) was recently synthesized, and its inhibitory actions were previously shown on histamine release and pro-inflammatory cytokine expression. In this study, a simultaneous quantification method was developed for the determination of SG-HQ2 and its possible metabolite, GA, in rat plasma using liquid chromatography with a tandem mass spectrometry (LC-MS/MS). After simple protein precipitation with acetonitrile including diclofenac (internal standard, IS), the analytes were chromatographed on a reversed phased column with a mobile phase of acetonitrile and water (60:40, v/v, including 0.1% formic acid). The ion transitions of the precursor to the product ion were principally protonated ion [M+H]⁺ at m/z 313.2→160.6 for SG-HQ2, and deprotonated ions [M-H]^- at m/z 168.7→124.9 for GA and 296.0→251.6 for the IS. The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This method was successfully applied to a pharmacokinetic study of SG-HQ2 after intravenous administration in rats.

Augmentative compression plating versus exchanging reamed nailing for nonunion of femoral shaft fracture after intramedullary nailing : A retrospective cohort study

Aim of the present study was to compare the outcomes between exchanging reamed nailing (ERN) and augmentative compression plating (ACP) in treatment of femoral shaft nonunion after intra-medullary nailing (IMN) retrospectively. A retrospective, multicentre study was performed with 188 patients (190 cases)with femoral shaft nonunion after IMN, who received therapy with either ERN (n = 92) for 44/92 (47.8%) cases of nonisthmal nonunions and 48/92 (52.2%) cases of isthmal nonunions or ACP (n = 98) for 48/98 (49%) cases of nonisthmal nonunions and 50/98 (51%) cases of isthmal nonunions. Operation time, intraoperative blood loss, time to union, union rate, postoperative draining volume and complication rate were compared between ERN and ACP group. After a mean follow-up of 4.6 years (range 1-8.1 years), the bone union occurred in 98/98 (100%) cases in -total ACP group versus 80/92 (87%) cases in total ERN group [odds ratio (OR) = 3.34, 95% confidence interval (CI) 0.8-1.6]. Twelve cases with re-nonunion in the total ERN group included 10/12 (83.3%) cases of nonisthmal nonunions and 2/12 (16.7%) cases of isthmal nonunion with cortical bone defect > 3 cm. The average time to union, the intraoperative blood loss and the complication rate in total ERN group were also both significantly more than that in total ACP group (p = 0.031, p = 0.042, p = 0.028). No -significant difference was found in the average operation time between the two total groups (p = 0.213). However, for nonisthmal nonunions, the mean operation time for ERN group was 126.8 ± 19.6 min in -comparison to ACP group (88.6 ± 15.2 min), significant difference was found between ERN group and ACP group (p = 0.021). ACP could obtain the higher bone union rate and shorter time to union than ERN in the treatment of femoral shaft nonunion after failed IMN. Especially for nonisthmal femoral shaft nonunions or isthmal.

Pharmacokinetic Interaction of Chrysin with Caffeine in Rats

Pharmacokinetic interaction of chrysin, a flavone present in honey, propolis and herbs, with caffeine was investigated in male Sprague-Dawley rats. Because chrysin inhibited CYP1A-selective ethoxyresorufin O-deethylase and methoxyresorufin O-demethylase activities in enriched rat liver microsomes, the pharmacokinetics of caffeine, a CYP 1A substrate, was studied following an intragastric administration with 100 mg/kg chrysin. In addition to the oral bioavailability of chrysin, its phase 2 metabolites, chrysin sulfate and chrysin glucuronide, were determined in rat plasma. As results, the pharmacokinetic parameters for caffeine and its three metabolites (i.e., paraxanthine, theobromine and theophylline) were not changed following chrysin treatment in vivo, despite of its inhibitory effect on CYP 1A in vitro. The bioavailability of chrysin was found to be almost zero, because chrysin was rapidly metabolized to its sulfate and glucuronide conjugates in rats. Taken together, it was concluded that the little interaction of chrysin with caffeine might be resulted from the rapid metabolism of chrysin to its phase 2 metabolites which would not have inhibitory effects on CYP enzymes responsible for caffeine metabolism.

Low nanomolar concentrations of Cucurbitacin-I induces G2/M phase arrest and apoptosis by perturbing redox homeostasis in gastric cancer cells in vitro and in vivo

Cucurbitacin-I (Cu-I, also known as Elatericin B or JSI-124) is developed to inhibit constitutive and abnormal activation of STAT3 in many cancers, demonstrating a potent anticancer activity by targeting disruption of STAT3 function. Here, we for the first time systematically studied the underlying molecular mechanisms of Cu-I-induced gastric cancer cell death both in vitro and in vivo. In our study, we show that Cu-I markedly inhibits gastric cancer cell growth by inducing G2/M phase cell cycle arrest and apoptosis at low nanomolar concentrations via a STAT3-independent mechanism. Notably, Cu-I significantly decreases intracellular GSH/GSSG ratio by inhibiting NRF2 pathway to break cellular redox homeostasis, and subsequently induces the expression of GADD45α in a p53-independent manner, and activates JNK/p38 MAPK signaling. Interestingly, Cu-I-induced GADD45α and JNK/p38 MAPK signaling form a positive feedback loop and can be reciprocally regulated by each other. Therefore, the present study provides new insights into the mechanisms of antitumor effects of Cu-I, supporting Cu-I as an attractive therapeutic drug in gastric cancer by modulating the redox balance.

Simultaneous determination of 3-O-acetyloleanolic acid and oleanolic acid in rat plasma using liquid chromatography coupled to tandem mass spectrometry

3-O-Acetyloleanolic acid (OAA) is a triterpenoid compound, and exerts an apoptosis in cancer cell lines, an inhibition of both atopic and allergic contact dermatitis in murine model, and a suppression of inflammatory bone loss in mice. OAA can be converted into oleanolic acid (OA) by hydrolysis in vivo, and OA exhibits several pharmacological effects as well. A liquid chromatographic method using tandem mass spectrometry (MS/MS) was developed for the simultaneous determination of OAA and OA in rat plasma. After liquid-liquid extraction with ethylacetate, both substances were chromatographed on a reversed phase column with a mobile phase of 0.1% formic acid aqueous solution and acetonitrile (1:9, v/v). The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of both substances over time following an intravenous administration of OAA in rats.

Epigenetic silencing of GDF1 disrupts SMAD signaling to reinforce gastric cancer development

Accumulating evidence reveals the effectiveness of epigenetic therapy in gastric cancer. However, the molecular mechanisms and targets underlying such therapeutic responses remain elusive. Herein, we report an aberrant yet therapeutically rectifiable epigenetic signaling in gastric carcinogenesis. Administration of DNA-demethylating drug 5-aza-2'-deoxycytidine (5-aza-dC) reduced gastric cancer incidence by ~74% (P < 0.05) in N-nitroso-N-methylurea-treated mice. Through genome-wide methylation scanning, novel promoter hypermethylation-silenced and drug-targeted genes were identified in the resected murine stomach tumors and tissues. We uncovered that growth/differentiation factor 1 (Gdf1), a member of the transforming growth factor-β superfamily, was silenced by promoter hypermethylation in control tumor-bearing mice, but became reactivated in 5-aza-dC-treated mice (P < 0.05). In parallel, the downregulated SMAD2/3 phosphorylation in gastric cancer was revived by 5-aza-dC in vivo. Such hypermethylation-dependent silencing and 5-aza-dC-mediated reactivation of GDF1-SMAD2/3 activity was conserved in human gastric cancer cells (P < 0.05). Subsequent functional characterization further revealed the antiproliferative activity of GDF1, which was exerted through activation of SMAD2/3/4-mediated signaling, transcriptional controls on p15, p21 and c-Myc cell-cycle regulators and phosphorylation of retinoblastoma protein. Clinically, hypermethylation and loss of GDF1 was significantly associated with reduced phosphorylated-SMAD2/3 and poor survival in stomach cancer patients (P < 0.05). Taken together, we demonstrated a causal relationship between DNA methylation and a tumor-suppressive pathway in gastric cancer. Epigenetic silencing of GDF1 abrogates the growth-inhibitory SMAD signaling and renders proliferation advantage to gastric epithelial cells during carcinogenesis. This study lends support to epigenetic therapy for gastric cancer chemoprevention and identifies a potential biomarker for prognosis.

Stillbirth: Genome-wide copy number variation profiling in archived placental umbilical cord samples with pathologic and clinical correlation

INTRODUCTION

Stillbirth remains a devastating health issue with 26,000 stillbirths occurring annually in the United States. Formalin-fixed, paraffin-embedded (FFPE) umbilical cord samples are available for many stillbirths. Our aim was to validate the use of these samples in identifying genetic variations in stillbirth through microarray analysis.

METHODS

This is a retrospective case-control study from a single institution of stillbirths ≥ 23 weeks gestational age and control liveborn infants. Fetal genomic DNA was extracted from FFPE umbilical cord samples of stillborn and control placentas, and genotyping was performed using the Illumina HumanOmniExpresss-12v1 Beadchip. Array results were verified with qPCR.

RESULTS

31 case-specific CNVs (17 deletions and 14 amplifications) with an average size of 294 kb for amplifications and 74 kb for deletions were identified among 94 FFPE samples (86 cases; 8 controls). In total 38 (44%) of the stillbirth samples had a CNV detected. Validation of a subset of microarray findings with qPCR confirmed deletions on 1p (2 cases), 11q (4 cases) and amplifications on 18 (1 case). Placental underperfusion changes were seen in stillborns with deletions on 1p, a region containing complement regulatory genes which have been shown to play a role in preeclampsia.

DISCUSSION

This study validated the use of archived FFPE umbilical cord samples for genome-wide copy number profiling in stillbirths, and demonstrates specific CNV deletions and amplifications. Microarray analysis in an expanded cohort of stillbirth FFPE samples has the potential to identify biomarkers involved in stillbirth pathogenesis.

Effects of baicalin on oral pharmacokinetics of caffeine in rats

Scutellaria baicalensis is one of the most widely used herbal medicines in East Asia. Because baicalein and baicalin are major components of this herb, it is important to understand the effects of these compounds on drug metabolizing enzymes, such as cytochrome P450 (CYP), for evaluating herb-drug interaction. The effects of baicalin and baicalein on activities of ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), benzyloxyresorufin O-debenzylase (BROD), p-nitrophenol hydroxylase and erythromycin N-demethylase were assessed in rat liver microsomes in the present study. In addition, the pharmacokinetics of caffeine and its three metabolites (i.e., paraxanthine, theobromine and theophylline) in baicalin-treated rats were compared with untreated control. As results, EROD, MROD and BROD activities were inhibited by both baicalin and baicalein. However, there were no significant differences in the pharmacokinetic parameters of oral caffeine and its three metabolites between control and baicalin-treated rats. When the plasma concentration of baicalin was determined, the maximum concentration of baicalin was below the estimated IC₅₀ values observed in vitro. In conclusion, baicalin had no effects on the pharmacokinetics of caffeine and its metabolites in vivo, following single oral administration in rats.

Effect of nitric oxide inhalation combined with high-frequency oscillatory ventilation on the prognosis of neonatal severe hypoxemia

OBJECTIVE

The current study aimed to analyze the short-term and long-term curative effects of nitric oxide (NO) inhalation combined with high-frequency oscillatory ventilation (HFOV) on neonatal severe hypoxemia.

MATERIALS AND METHODS

A total of 98 neonates meeting the inclusion criteria were retrospectively analyzed. The control group comprised of 48 neonates and the NO inhalation group consisted of 50 neonates. In the control group, conventional mechanical ventilation was replaced by HFOV. In the experimental group, NO inhalation combined with HFOV was performed. The death rates within 28 days, mechanical ventilation and oxygen therapy time, and complications in both groups were observed. The survivors in both groups were followed up for 18 months for neural development evaluation.

RESULTS

The treatment group showed a significantly lower death rate and noticeably shorter mechanical ventilation and oxygen therapy time than the control group (8% vs. 22.9% with t = 4.20 andp < 0.05; 5.84 ± 3.36 days vs. 8.05 ± 5.48 days with t = 2.42 and p < 0.05; and 8.02 ± 4.31 days vs. 12.45 ± 5.14 days with t = 4.63 and p < 0.001). They did not show significant differences with regards to the complications and the incidences of cerebral palsy, hearing and visual impairments, and severe nervous damage (p > 0.05).

CONCLUSION

NO inhalation combined with HFOV significantly decreases the death rate of neonates with severe hypoxemia and reduces their mechanical ventilation and oxygen therapy time. It does not increase early adverse effects or affect long-term neurodevelopment.

Valley-polarized interlayer conduction of anisotropic Dirac fermions in SrMnBi2

We report the valley-selective interlayer conduction of SrMnBi(2) under in-plane magnetic fields. The c-axis resistivity of SrMnBi(2) shows clear angular magnetoresistance oscillations indicating coherent interlayer conduction. Strong fourfold variation of the coherent peak in the c-axis resistivity reveals that the contribution of each Dirac valley is significantly modulated by the in-plane field orientation. This originates from anisotropic Dirac Fermi surfaces with strong disparity in the momentum-dependent interlayer coupling. Furthermore, we found a signature of broken valley symmetry at high magnetic fields. These findings demonstrate that a quasi-two-dimensional anisotropic Dirac system can host a valley-polarized interlayer current through magnetic valley control.