Low-Temperature Gas Plasma Combined with Antibiotics for the Reduction of Methicillin-Resistant Staphylococcus aureus Biofilm Both In Vitro and In Vivo.

Biofilm infections in wounds seriously delay the healing process, and methicillin-resistant Staphylococcus aureus is a major cause of wound infections. In addition to inactivating micro-organisms, low-temperature gas plasma can restore the sensitivity of pathogenic microbes to antibiotics. However, the combined treatment has not been applied to infectious diseases. In this study, low-temperature gas plasma treatment promoted the effects of different antibiotics on the reduction of S. aureus biofilms in vitro. Low-temperature gas plasma combined with rifampicin also effectively reduced the S. aureus cells in biofilms in the murine wound infection model. The blood and histochemical analysis demonstrated the biosafety of the combined treatment. Our findings demonstrated that low-temperature gas plasma combined with antibiotics is a promising therapeutic strategy for wound infections.

Periplaneta americana Extracts Accelerate Liver Regeneration via a Complex Network of Pathways.

Successful recovery from hepatectomy is partially contingent upon the rate of residual liver regeneration. The traditional Chinese medicines known as Periplaneta americana extracts (PAEs) positively influence wound healing by promoting tissue repair. However, the effect of PAEs on liver regeneration is unknown. We used a mouse liver regeneration model after 70% partial hepatectomy (PH) and a hepatocyte culture to determine whether PAEs can promote liver regeneration as effectively as skin regeneration and establish their modes of action. L02 cells were divided into serum-starved control (NC) and three PAEs (serum starvation + 0.1 mg/ml, 0.5 mg/ml, or 1 mg/ml PAEs) groups. L02 cell proliferation was assessed at 24 h, 48 h, and 72 h by CCK-8 assay. Forty male C57 mice were randomly divided into control (NC), normal saline (NS), PAEs400 (400 mg/kg/d), and PAEs800 (800 mg/kg/d) groups (n = 10 per group). The NS and both PAEs groups were administered normal saline and PAEs, respectively, by gavage for 10 days. Two hours after the tenth gavage, the NS and both PAEs groups were subjected to 70% PH and the residual liver was harvested after 48 h. The hepatic regeneration rate was evaluated and hepatocyte proliferation was estimated by immunohistochemical (IHC) staining for Ki-67. Twelve DEG libraries (three samples per group) were prepared and sequencing was performed in an Illumina HiSeq 2000 (Mus_musculus) at the Beijing Genomics Institute. The genes expressed in the liver tissues and their expression profiles were analyzed by bioinformatics. KEGG was used to annotate, enrich, and analyze the pathways. PAEs promoted hepatocyte proliferation in vitro and in vivo and accelerated mouse liver regeneration after 70% PH. The screening criteria were fold change (FC) ≥ 2 and q-value < 0.001. We identified 1,092 known DEGs in PAEs400 and PAEs800. Of these, 153 were categorized in cellular processes. The KEGG analysis revealed that the aforementioned DEGs participated in several signaling pathways closely associated with cell proliferation including PI3K-Akt, MAPK, Apelin, Wnt, FoxO, mTOR, Ras, VEGF, ErbB, Hippo, and AMPK. It was concluded that PAEs can effectively improve liver regeneration via the synergistic activation of different signaling pathways.

Mechanism of Virus Inactivation by Cold Atmospheric-Pressure Plasma and Plasma-Activated Water.

Viruses cause serious pathogenic contamination that severely affects the environment and human health. Cold atmospheric-pressure plasma efficiently inactivates pathogenic bacteria; however, the mechanism of virus inactivation by plasma is not fully understood. In this study, surface plasma in argon mixed with 1% air and plasma-activated water was used to treat water containing bacteriophages. Both agents efficiently inactivated bacteriophages T4, Φ174, and MS2 in a time-dependent manner. Prolonged storage had marginal effects on the antiviral activity of plasma-activated water. DNA and protein analysis revealed that the reactive species generated by plasma damaged both nucleic acids and proteins, consistent with the morphological examination showing that plasma treatment caused the aggregation of bacteriophages. The inactivation of bacteriophages was alleviated by the singlet oxygen scavengers, demonstrating that singlet oxygen played a primary role in this process. Our findings provide a potentially effective disinfecting strategy to combat the environmental viruses using cold atmospheric-pressure plasma and plasma-activated water.IMPORTANCE Contamination with pathogenic and infectious viruses severely threatens human health and animal husbandry. Current methods for disinfection have different disadvantages, such as inconvenience and contamination of disinfection by-products (e.g., chlorine disinfection). In this study, atmospheric surface plasma in argon mixed with air and plasma-activated water was found to efficiently inactivate bacteriophages, and plasma-activated water still had strong antiviral activity after prolonged storage. Furthermore, it was shown that bacteriophage inactivation was associated with damage to nucleic acids and proteins by singlet oxygen. An understanding of the biological effects of plasma-based treatment is useful to inform the development of plasma into a novel disinfecting strategy with convenience and no by-product.

Cold atmospheric-pressure plasma induces DNA-protein crosslinks through protein oxidation.

Reactive oxygen and nitrogen species (ROS and RNS) generated by cold atmospheric-pressure plasma could damage genomic DNA, although the precise types of these DNA damage induced by plasma are poorly characterized. Understanding plasma-induced DNA damage will help to elucidate the biological effect of plasma and guide the application of plasma in ROS-based therapy. In this study, it was shown that ROS and RNS generated by physical plasma could efficiently induce DNA-protein crosslinks (DPCs) in bacteria, yeast, and human cells. An in vitro assay showed that plasma treatment resulted in the formation of covalent DPCs by activating proteins to crosslink with DNA. Mass spectrometry and hydroperoxide analysis detected oxidation products induced by plasma. DPC formation were alleviated by singlet oxygen scavenger, demonstrating the importance of singlet oxygen in this process. These results suggested the roles of DPC formation in DNA damage induced by plasma, which could improve the understanding of the biological effect of plasma and help to develop a new strategy in plasma-based therapy including infection and cancer therapy.

Gas Plasma Pre-treatment Increases Antibiotic Sensitivity and Persister Eradication in Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of serious nosocomial infections, and recurrent MRSA infections primarily result from the survival of persister cells after antibiotic treatment. Gas plasma, a novel source of ROS (reactive oxygen species) and RNS (reactive nitrogen species) generation, not only inactivates pathogenic microbes but also restore the sensitivity of MRSA to antibiotics. This study further found that sublethal treatment of MRSA with both plasma and plasma-activated saline increased the antibiotic sensitivity and promoted the eradication of persister cells by tetracycline, gentamycin, clindamycin, chloramphenicol, ciprofloxacin, rifampicin, and vancomycin. The short-lived ROS and RNS generated by plasma played a primary role in the process and induced the increase of many species of ROS and RNS in MRSA cells. Thus, our data indicated that the plasma treatment could promote the effects of many different classes of antibiotics and act as an antibiotic sensitizer for the treatment of antibiotic-resistant bacteria involved in infectious diseases.

Activation of peroxisome proliferator-activated receptor-γ by a 12/15-lipoxygenase product of arachidonic acid: a possible neuroprotective effect in the brain after experimental intracerebral hemorrhage.

OBJECTIVE In this study, the authors investigated the involvement of 15( S)-hydroxyeicosatetraenoic acid (15(S)-HETE) in the regulation of peroxisome proliferator-activated receptor-γ (PPARγ) after intracerebral hemorrhage (ICH) and its effects on hemorrhage-induced inflammatory response and oxidative stress in an experimental rodent model. METHODS To simulate ICH in a rat model, the authors injected autologous whole blood into the right striatum of male Sprague-Dawley rats. The distribution and expression of 12/15-lipoxygenase (12/15-LOX) were determined by immunohistochemistry and Western blot analysis, respectively. Immunofluorescent double labeling was used to study the cellular localization of 12/15-LOX, and 15(S)-HETE was measured with a 15(S)-HETE enzyme immunoassay kit. Neurological deficits in the animals were assessed through behavioral testing, and apoptotic cell death was determined with terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick-end labeling. RESULTS Rats with ICH had increased expression of 12/15-LOX predominantly in neurons and also in oligodendrocytes, astrocytes, and microglia. Moreover, ICH elevated production of 15(S)-HETE in the brain area ipsilateral to the blood injection. The PPARγ agonist, exogenous 15(S)-HETE, significantly increased PPARγ protein levels and increased PPARγ-regulated gene (i.e., catalase) expression in the ICH rats. Reduced expression of the gene for the proinflammatory protein nuclear factor κB coincided with decreased neuron damage and improved functional recovery from ICH. A PPARγ antagonist, GW9662, reversed the effects of exogenous 15(S)-HETE on the PPARγ-regulated genes. CONCLUSIONS The induction of 15(S)-HETE during simulated ICH suggests generation of endogenous signals of neuroprotection. The effects of exogenous 15(S)-HETE on brain hemorrhage-induced inflammatory responses and oxidative stress might be mediated via PPARγ.

Experimental intracerebral haemorrhage: description of a semi-coagulated autologous blood model in rats.

OBJECTIVES: A major limitation of intracerebral haemorrhage (ICH) research is the lack of reproducible animal models. The purpose of the present study was to produce experimental haemorrhages and to characterise the lesion by histology and behaviour in rats. METHODS: A total of 180 male SD rats were anaesthetised with chloral hydrate. Rats were placed in a stereotactic frame, and a microinjector was introduced through a burr hole into the right striatum. Each rat received an injection of 60 µL of semi-coagulated autologous whole blood over 6  minutes. The needle was slowly withdrawn 40 minutes after the injection. Control rat had only needle insertion. Time courses of haematoma resolution and pathological changes after intrastriatal injection of semi-coagulated autologous blood were observed. Neurological status was evaluated on days 1, 3, 5, 7, 14 and 21.The behavioural tests used were forelimb placing and a corner turn test. RESULTS: Rats with ICH had a marked, persistent neurological deficit and a highly reproduced haematoma in shape and size. Histologically, haematoma was observed at 1, 3, 5 and 7 days and cysts at 3 weeks. Behavioural abnormalities were present for 14  days, with the recovery of function occurring during the third week. CONCLUSIONS: The present ICH model in rats produces a consistent neurological deficit and reproducible haematoma in shape and size. This model could be useful to evaluate the future pharmaceutical therapies in ICH.

Genetic polymorphisms of IFNG and IFNGR1 in association with the risk of pulmonary tuberculosis.

OBJECTIVE: Genetic host factors play an important role in controlling individual's susceptibility to the pathogen. This study aims to explore the single and joint effect of genetic polymorphisms of interferon-gamma (IFNG) and its receptor (IFNGR1) in association with the pulmonary tuberculosis in a Chinese Han population. METHODS: This population-based case control study consisted of 1434 pulmonary tuberculosis patients and 1412 healthy controls. Six tag SNPs in IFNG/IFNGR1 were genotyped using TaqMan allelic discrimination technology. The logistic regression model was carried out to analyze the associations between the genotypes and haplotypes and the risk of tuberculosis by calculating the odds ratio (OR) and 95% confidence interval (CI). RESULTS: After the Bonferroni correction for multiple comparisons, three SNPs (rs2234711, rs1327475 and rs7749390) in IFNGR1 gene were observed to be significantly associated with the altered risks of tuberculosis. For the SNP rs2234711, individuals carrying C allele (vs. T) showed a decreased risk, with the adjusted OR(95% CI) of 0.82(0.76-0.91). The additive model revealed that each additional allele contributed about 14% decreased risk (OR: 0.86, 95% CI: 0.77-0.95). Moreover, we observed a strong linkage disequilibrium between rs2234711 and rs3799488. Compared with the common rs2234711C-rs3799488C haplotype, the haplotype rs2234711T-rs3799488C contributed to a significant increase in the risk of tuberculosis (adjusted OR: 1.24, 95% CI: 1.09-1.41). CONCLUSIONS: Our results suggest that genetic polymorphisms in IFNGR1 gene are involved in the risk of tuberculosis in the Chinese population. Future studies should include a comprehensive sequencing analysis to identify the specific causative sequence variants underlying the observed associations.

Promoter methylation of BRCA1 in the prognosis of breast cancer: a meta-analysis.

The inactivation of BRCA1 by epigenetic alterations is a critical event in breast tumorigenesis, which may potentially be used as a prognostic marker for patients with breast cancer. The present study systematically reviewed the promoter methylation of BRCA1 and its relationship to the clinical outcomes of breast cancer patients. We performed a meta-analysis following the PRISMA guideline. Relevant articles were identified by searching PubMed, Web of Science and Embase database until August 2013. The pooled hazard ratio (HR) and 95 % confidence interval (CI) were applied to estimate the effect of BRCA1 methylation. Random or fixed effect model was chosen based on the heterogeneity analysis. A total of 3,205 patients from nine eligible studies were included in the meta-analysis. BRCA1 methylation was found to be significantly correlated with a poor overall survival of breast cancer, with the combined HR (95 % CI) of 2.02 (1.35-3.03). After adjusting for potential confounders using the Cox regression model, the pooled HR (95 % CI) of BRCA1 methylation on patients' overall survival was 1.38 (1.04-1.84). If we used the disease-free survival as the outcome, the combined HR (95 % CI) was 2.89 (1.73-4.83) for univariate analysis and 3.92 (95 % CI 1.49-10.32) for multivariate analysis, respectively. Subgroup analysis of specimen types revealed that the pooled HR (95 % CI) for overall survival was 1.48 (1.22-1.81) when using formalin-fixed paraffin-embedded (FFPE) specimen and 1.38 (0.16-11.84) when using fresh frozen tissues. As for the disease-free survival, the pooled HR (95 % CI) was 2.47 (1.33-4.58) when using FFPE specimen and 2.78 (1.47-5.28) when using fresh frozen tissues. As a conclusion, the present meta-analysis provides evidence that BRCA1 methylation is associated with a poor survival of breast cancer patients. Our findings underscore the clinical relevance of aberrant epigenetic alteration as a promising biomarker for the prognosis of human cancers.

A systematic review of hypermethylation of p16 gene in esophageal cancer.

BACKGROUND: Inactivation of cell-cycle regulating gene p16, resulting from epigenetic alteration, is common in the carcinogenesis of human cancers. The aim of this study is to offer a systematic review on the aberrant methylation of p16 gene in esophageal cancer. METHODS: We performed a meta-analysis referring to the guidelines of PRISMA. We searched for articles published from 1996 to 31 May 2012 using PubMed and China National Knowledge Infrastructure (CNKI) database. Additional database including Web of Science and EMBASE were also searched for related articles. The random or fixed effect model was applied to estimate the pooled frequency of DNA methylation based on the heterogeneity analysis. Subgroup analyses were performed according to the histological type, study area, and tumor grade. RESULTS: This meta-analysis included 39 articles related to the methylation studies on p16 gene in cancer tissues and 7 articles using blood samples. The summarized frequency of DNA methylation detected in cancer tissues was 0.53 (95% CI: 0.44-0.61). With the increase of tumor differentiation grades, the frequency of DNA methylation increased accordingly (well differentiated: 0.37; moderately differentiated: 0.61; poorly differentiated: 0.63). We further summarized the methylation of p16 gene detected in patient's peripheral blood samples. The pooled frequency was 0.33 (95% CI: 0.17-0.49), which was lower than that detected in cancer tissues. CONCLUSION: This meta-analysis revealed the elevated frequency of DNA methylation of p16 gene in esophageal cancer, which indicated future potential application of this biomarker in early detection as well as the prognosis of the disease.

A neglected issue on sexual well-being following breast cancer diagnosis and treatment among Chinese women.

BACKGROUND: Changes to sexual well-being can be one of the most problematic quality of life issues following the diagnosis and treatment of breast cancer. The objectives of the present study were to evaluate changes to sexual well-being following breast cancer, to expand upon the existing body of knowledge pertaining to breast cancer and sexuality, and to provide the necessary information for implementing future interventions that may help improve the quality of life in breast cancer patients. METHODS: This study was mixed with qualitative and quantitative designs. Twenty patients with breast cancer were recruited for in-depth interviews. The central questions covered a patient's cancer experience and perceptions of sexual activities following breast cancer. According to the findings of the qualitative study, we performed a quantitative study using a structured questionnaire to collect data on patient's experience and attitude to sexual well-being following breast cancer diagnosis and treatment. RESULTS: Based on the qualitative analysis, seven main themes emerged: (1) Decrease in sexual frequency; (2) Lack of sexual interest; (3) Menopausal symptoms; (4) Body image changes; (5) Effects on marital relationship; (6) Misconceptions about sex; (7) The need for professional consultation. Results from the quantitative study further supported the findings from the qualitative analysis, where changes to sexual well-being were common following cancer diagnosis and treatment and it was a neglected issue among Chinese women. CONCLUSIONS: The present study highlights the significant changes to sexual well-being following breast cancer, in addition to the lack of knowledge and misconceptions of sexual activity among patients. Addressing these problems will help improve a patient's quality of life. The findings of this study could help healthcare professionals recognize the sexual issues faced by women with breast cancer and ultimately promote a healthy life.

Loss of expression of the differentially expressed in adenocarcinoma of the lung (DAL-1) protein is associated with metastasis of non-small cell lung carcinoma cells.

The differentially expressed in adenocarcinoma of the lung-1 (DAL-1) protein is a member of the membrane-associated cytoskeleton protein 4.1 family. This protein was previously found to be downregulated or lost in more than half of primary non-small cell lung cancers (NSCLC). In this study, the relationship between DAL-1 expression and NSCLC metastasis was examined. DAL-1 mRNA and protein levels were measured in NSCLC cell lines and in tumor cells isolated from the pleural fluid of NSCLC patients clinically diagnosed with distant metastases to the bone or brain. The results revealed that DAL-1 expression was observed in two (GLC-82 and NCI-H460) out of seven metastatic NSCLC cell lines examined. DAL-1 expression was not observed in the cells isolated from the pleural fluid in nine out of ten patients. Overexpression of DAL-1 in A549 cells, a cell line lacking endogenous DAL-1, inhibited cell migration and invasion by approximately 38 and 48 %, respectively. In contrast, DAL-1 knockdown in NCI-H460 cells enhanced the migration and invasion potential of this cell line 4.6- and 3-fold, respectively. Furthermore, DAL-1 promoter methylation was observed in six of nine pleural fluid NSCLC cell isolates and in two cell lines (A549 and H1299), as evidenced by a lack of endogenous DAL-1. Demethylation in A549 cells successfully restored DAL-1 mRNA and protein expression levels, resulting in a parallel remarkable inhibition of migration and invasion. These results indicated that DAL-1 was pivotal in triggering NSCLC migration and invasion and that loss of DAL-1 expression was due to the epigenetic methylation.

[Relationship between TIMP-3 expression and promoter methylation of TIMP-3 gene in hepatocellular carcinoma].

OBJECTIVE: To investigate further the possible mechanism of carcinogenesis and portal invasion of hepatocellular carcinoma (HCC). METHODS: Samples of the primary tumors, cancer cells emboli in the portal veins and normal liver tissues adjacent to the tumor were collected from 20 cases of primary HCC. Expression of TIMP-3 (tissue inhibitor of metalloproteinases-3) protein was detected using Western blot. Expression of TIMP-3 mRNA was detected by RT-PCR. Methylation of TIMP-3 gene promoter was detected using methylation-specific PCR (MSP). RESULTS: Expression of TIMP-3 protein and mRNA were obtained in all of the normal liver tissues adjacent to tumor. However, loss of TIMP-3 protein expression was found in 5 and 36 cases respectively in the primary tumors and tumor cell emboli in portal veins. Expression of TIMP-3 protein and mRNA in primary tumors and tumor emboli were significantly lower than that in the normal liver tissues. Promoter methylation of TIMP-3 gene could be detected in primary tumors (7 cases) and cancerous emboli (9 cases) in HCC, while no methylation found in normal liver tissues. In all the HCC cases with promoter gene methylation including primary tumors and cancerous emboli in portal veins, 13 cases showed complete loss and 6 cases showed low expression of TIMP-3 protein and mRNA. Promoter methylation of TIMP-3 was noticed not related with the histological grading of HCC. CONCLUSIONS: There is a close relationship between loss or low expressions of TIMP-3 and carcinogenesis and portal invasion of HCC. The loss and low expression of TIMP-3 gene and protein were caused by methylation of the gene promoter.