Treatment outcomes amongst older people with HIV infection receiving antiretroviral therapy

OBJECTIVES

There is conflicting data regarding the response of older people with HIV (PWH) to antiretroviral therapy (ART). The objective of this study was to evaluate the long-term immunological and virological responses, changes in regimen, and adverse drug reactions (ADRs) in older participants (50+ years) compared with younger (18-34 years) and middle-aged (35-49 years) PWH.

METHODS

A retrospective review of medical records was conducted on 1622 participants who received ART in Yunnan Province, China, from 2010 to 2019. The study compared CD4+ T-cell counts, CD4+/CD8+ ratio, and relative numbers between different groups using the Kruskal-Wallis test. Cox proportional hazards regression models were used to identify variables associated with the occurrence of immune reconstitution insufficiency. The rates of immune reconstitution, incidence of ADRs, and rates of treatment change were analyzed using the chi-squared test or Fisher's exact test.

RESULTS

Over 95% achieved viral load 200 copies/ml or less, with no age-related difference. However, older participants exhibited significantly lower CD4+ T-cell counts and CD4+/CD8+ recovery post-ART (P < 0.001), with only 32.21% achieving immune reconstitution (compared with young: 52.16%, middle-aged: 39.29%, P < 0.001) at the end of follow-up. Middle-aged and elderly participants changed ART regimens more because of ADRs, especially bone marrow suppression and renal dysfunction.

CONCLUSION

Although the virological response was consistent across age groups, older individuals showed poorer immune responses and higher susceptibility to side effects. This underscores the need for tailored interventions and comprehensive management for older patients with HIV.

A ring-like accretion structure in M87 connecting its black hole and jet

The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of [Formula: see text] Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow.

Euonymine inhibits in-stent restenosis through enhancing contractile phenotype of vascular smooth muscle cells via modulating the PTEN/AKT/mTOR signaling pathway

BACKGROUND

Percutaneous coronary intervention (PCI) is an effective treatment for acute myocardial infarction, but the postoperative in-stent re-stenosis (ISR) remains a major risk factor that affects the prognosis of PCI. Clinically, drug-eluting stents (DES) are widely applied to prevent and treat ISR. However, only a few stent coating drugs are currently available for clinical use, including paclitaxel and rapamycin (sirolimus) and their derivatives. These stent-coated drugs have led to a decrease in restenosis rates, but the major adverse outcomes, such as delayed endothelial healing and increased in-stent thrombosis, seriously reduce their therapeutic effects.

PURPOSE

Herein, we explored the potential efficacy of Euonymine (Euo), an alkaloid extracted from Tripterygium Hypoglaucum (Levl) Hutch (THH, Lei gong Teng), for the prevention against ISR after PCI.

STUDY DESIGN

Our study depicts the potential efficacy of Euo in treating ISR and explores its mechanism with in vitro and in vivo models.

METHODS

Primary vascular smooth muscle cells (VSMCs) from the rabbit thoracic aorta were cultured, and the proliferation and migration of VSMCs were monitored. Apoptosis was measured by Transmission Electron Microscopy and TUNEL staining assay. Protein and gene levels were measured to explore the underlying molecular mechanisms. In vivo models of porcine coronary implantation and rabbit carotid balloon injury are used to validate the efficacy of Euo in inhibiting ISR after PCI.

RESULTS

With an ox-LDL-injured cell model, we showed that Euo suppressed the proliferation and migration of the rabbit thoracic aorta primary VSMCs, while inducing their apoptosis. We next established a rabbit carotid balloon injury model in which the phosphorylation levels of PI3K and AKT1 (Ser473) as well as mTOR activity were significantly elevated compared to the sham-operated control. These activities were significantly attenuated by the Euo intervention. Additionally, the balloon angioplasty significantly increased the expression of Bcl-2, while decreased the expression of Bax and caspase-3. Euo intervention significantly increased the ratio of Bax/Bcl-2 and the level of caspase-3. Taken together, Euo may enhance the VSMCs contractile phenotype by modulating the PTEN/AKT/mTOR signaling pathway. Furthermore, with two in vivo models, the porcine coronary artery implantation model, and the rabbit carotid balloon injury model, we demonstrated that Euo-eluting stents indeed inhibited ISR after PCI.

CONCLUSION

For the first time, this study delineates the potential efficacy of Euo, derived from Tripterygium Hypoglaucum (Levl) Hutch, in ameliorating ISR after PCI with two in vivo models. The phytochemical targets PTEN/AKT/mTOR signaling pathway to increase the contractile phenotype of VSMCs and exerts anti-proliferative, anti-migratory as well as pro-apoptotic effects, thereby inhibiting the ISR.

Whole-genome resequencing of worldwide wild and domestic sheep elucidates genetic diversity, introgression and agronomically important loci

Domestic sheep and their wild relatives harbor substantial genetic variants that can form the backbone of molecular breeding, but their genome landscapes remain understudied. Here, we present a comprehensive genome resource for wild ovine species, landraces and improved breeds of domestic sheep, comprising high-coverage (∼16.10×) whole genomes of 810 samples from 7 wild species and 158 diverse domestic populations. We detected, in total, ∼121.2 million single nucleotide polymorphisms, ∼61 million of which are novel. Some display significant (P < 0.001) differences in frequency between wild and domestic species, or are private to continent-wide or individual sheep populations. Retained or introgressed wild gene variants in domestic populations have contributed to local adaptation, such as the variation in the HBB associated with plateau adaptation. We identified novel and previously reported targets of selection on morphological and agronomic traits such as stature, horn, tail configuration, and wool fineness. We explored the genetic basis of wool fineness and unveiled a novel mutation (chr25: T7,068,586C) in the 3′-UTR of IRF2BP2 as plausible causal variant for fleece fiber diameter. We reconstructed prehistorical migrations from the Near Eastern domestication center to South-and-Southeast Asia and found two main waves of migrations across the Eurasian Steppe and the Iranian Plateau in the Early and Late Bronze Ages. Our findings refine our understanding of genome variation as shaped by continental migrations, introgression, adaptation, and selection of sheep.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Decreased Antibiotic Susceptibility in Pseudomonas aeruginosa Surviving UV Irradition

Given its excellent performance against the pathogens, UV disinfection has been applied broadly in different fields. However, only limited studies have comprehensively investigated the response of bacteria surviving UV irradiation to the environmental antibiotic stress. Here, we investigated the antibiotic susceptibility of Pseudomonas aeruginosa suffering from the UV irradiation. Our results revealed that UV exposure may decrease the susceptibility to tetracycline, ciprofloxacin, and polymyxin B in the survival P. aeruginosa. Mechanistically, UV exposure causes oxidative stress in P. aeruginosa and consequently induces dysregulation of genes contributed to the related antibiotic resistance genes. These results revealed that the insufficient ultraviolet radiation dose may result in the decreased antibiotic susceptibility in the pathogens, thus posing potential threats to the environment and human health.

Paternal Origins and Migratory Episodes of Domestic Sheep

The domestication and subsequent global dispersal of livestock are crucial events in human history, but the migratory episodes during the history of livestock remain poorly documented [1-3]. Here, we first developed a set of 493 novel ovine SNPs of the male-specific region of Y chromosome (MSY) by genome mapping. We then conducted a comprehensive genomic analysis of Y chromosome, mitochondrial DNA, and whole-genome sequence variations in a large number of 595 rams representing 118 domestic populations across the world. We detected four different paternal lineages of domestic sheep and resolved, at the global level, their paternal origins and differentiation. In Northern European breeds, several of which have retained primitive traits (e.g., a small body size and short or thin tails), and fat-tailed sheep, we found an overrepresentation of MSY lineages y-HC and y-HB, respectively. Using an approximate Bayesian computation approach, we reconstruct the demographic expansions associated with the segregation of primitive and fat-tailed phenotypes. These results together with archaeological evidence and historical data suggested the first expansion of early domestic hair sheep and the later expansion of fat-tailed sheep occurred ∼11,800-9,000 years BP and ∼5,300-1,700 years BP, respectively. These findings provide important insights into the history of migration and pastoralism of sheep across the Old World, which was associated with different breeding goals during the Neolithic agricultural revolution.

Chlorine disinfection promotes the exchange of antibiotic resistance genes across bacterial genera by natural transformation

Chlorine disinfection to drinking water plays an important role in preventing and controlling waterborne disease outbreaks globally. Nevertheless, little is known about why it enriches the antibiotic resistance genes (ARGs) in bacteria after chlorination. Here, ARGs released from killed antibiotic-resistant bacteria (ARB), and culturable chlorine-injured bacteria produced in the chlorination process as the recipient, were investigated to determine their contribution to the horizontal transfer of ARGs during disinfection treatment. We discovered Escherichia coli, Salmonella aberdeen, Pseudomonas aeruginosa and Enterococcus faecalis showed diverse resistance to sodium hypochlorite, and transferable RP4 could be released from killed sensitive donor consistently. Meanwhile, the survival of chlorine-tolerant injured bacteria with enhanced cell membrane permeabilisation and a strong oxidative stress-response demonstrated that a physiologically competent cell could be transferred by RP4 with an improved transformation frequency of up to 550 times compared with the corresponding untreated bacteria. Furthermore, the water quality factors involving chemical oxygen demand (CODMn), ammonium nitrogen and metal ions (Ca2+ and K+) could significantly promote above transformation frequency of released RP4 into injured E. faecalis. Our findings demonstrated that the chlorination process promoted the horizontal transfer of plasmids by natural transformation, which resulted in the exchange of ARGs across bacterial genera and the emergence of new ARB, as well as the transfer of chlorine-injured opportunistic pathogen from non-ARB to ARB. Considering that the transfer elements were quite resistant to degradation through disinfection, this situation poses a potential risk to public health.

Whole-genome resequencing of wild and domestic sheep identifies genes associated with morphological and agronomic traits

Understanding the genetic changes underlying phenotypic variation in sheep (Ovis aries) may facilitate our efforts towards further improvement. Here, we report the deep resequencing of 248 sheep including the wild ancestor (O. orientalis), landraces, and improved breeds. We explored the sheep variome and selection signatures. We detected genomic regions harboring genes associated with distinct morphological and agronomic traits, which may be past and potential future targets of domestication, breeding, and selection. Furthermore, we found non-synonymous mutations in a set of plausible candidate genes and significant differences in their allele frequency distributions across breeds. We identified PDGFD as a likely causal gene for fat deposition in the tails of sheep through transcriptome, RT-PCR, qPCR, and Western blot analyses. Our results provide insights into the demographic history of sheep and a valuable genomic resource for future genetic studies and improved genome-assisted breeding of sheep and other domestic animals.

Osteoking improves OP rat by enhancing HSP90‑β expression

Osteoporosis (OP) is a chronic bone disease that affects individuals worldwide. Osteoporosis is primarily asymptomatic, and patients with OP suffer from pain, inconvenience, economic pressure and osteoporotic fracture (OPF). Osteoking, a Traditional Chinese Medicine compound that originates from the Yi ethnic group, has been used for a number of years to treat fractures. In our previous study, osteoking exhibited therapeutic effects on rats with OPF by promoting calcium deposition. Based on bioinformatics and network pharmacology analyses of a component‑target‑disease database, heat shock protein HSP 90‑β (HSP90‑β), also known as HSP90‑β, was identified to be a key target of osteoking in OP. High HSP90‑β expression levels were observed in osteoporotic rats and rat bone mesenchymal stem cells (rBMSCs) following osteoking treatment. After 12 weeks of administration in vivo, there was increased bone mineral density (BMD) (P<0.05), increased bone alkaline phosphatase (P<0.05), and improved bone microstructure in the osteoking group compared with those of the negative control group. In vitro, increased calcium deposition in rBMSCs was observed after 4 weeks of osteoking treatment. These results suggest that the mechanisms of osteoking are closely associated with HSP90‑β and activate the bone morphogenetic protein (BMP) signalling pathway, primarily through BMP‑2. Osteoking treatment improves OP in rats by enhancing HSP90‑β expression.

miR‑378a‑3p inhibits cellular proliferation and migration in glioblastoma multiforme by targeting tetraspanin 17

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor and patients with this disease tend to have poor clinical outcome. MicroRNAs (miRs) are important regulators of a number of key pathways implicated in tumor pathogenesis. Recently, the expression of miR‑378 was shown to be dysregulated in several different types of cancer, including gastric cancer, colorectal cancer and oral carcinoma. Additional studies have demonstrated that miR‑378 may serve as a potential therapeutic target against human breast cancer. However, the underlying mechanisms and potential targets of miR‑378a‑3p involved in GBM remain unknown. The aim of the present of was to determine the effects of miR‑378a‑3p and its potential targets. Tetraspanin 17 (TSPAN17) is involved in the neoplastic events in GBM and is a member of the tetraspanin family of proteins. The tetraspanins are involved in the regulation of cell growth, migration and invasion of several different types of cancer cell lines, and may potentially act as an oncogene associated with GBM pathology. The results of the present study showed that high miR‑378a‑3p and low TSPAN17 expression levels were associated with improved survival in patients with GBM. Additionally, high levels of TSPAN17 were linked to the poor prognosis of patients with GBM aged 50‑60, larger tumor sizes (≥5 cm) and an advanced World Health Organization stage. TSPAN17 was identified and confirmed as a direct target of miR‑378a‑3p using a luciferase reporter assay in human glioma cell lines. Overexpression of miR‑378a‑3p in either of U87MG or MT‑330 cells decreased the expression of TSPAN17, promoted apoptosis and decreased proliferation, migration and invasion. Overexpression of TSPAN17 attenuated the aforementioned effects induced by miR‑378a‑3p overexpression. The present study indicated that miR‑378a‑3p suppresses the progression of GBM by reducing TSPAN17 expression, and may thus serve as a potential therapeutic target for treating patients with GBM.

The Genome Landscape of Tibetan Sheep Reveals Adaptive Introgression from Argali and the History of Early Human Settlements on the Qinghai-Tibetan Plateau

Tibetan sheep are the most common and widespread domesticated animals on the Qinghai-Tibetan Plateau (QTP) and have played an essential role in the permanent human occupation of this high-altitude region. However, the precise timing, route, and process of sheep pastoralism in the QTP region remain poorly established, and little is known about the underlying genomic changes that occurred during the process. Here, we investigate the genomic variation in Tibetan sheep using whole-genome sequences, single nucleotide polymorphism arrays, mitochondrial DNA, and Y-chromosomal variants in 986 samples throughout their distribution range. We detect strong signatures of selection in genes involved in the hypoxia and ultraviolet signaling pathways (e.g., HIF-1 pathway and HBB and MITF genes) and in genes associated with morphological traits such as horn size and shape (e.g., RXFP2). We identify clear signals of argali (Ovis ammon) introgression into sympatric Tibetan sheep, covering 5.23-5.79% of their genomes. The introgressed genomic regions are enriched in genes related to oxygen transportation system, sensory perception, and morphological phenotypes, in particular the genes HBB and RXFP2 with strong signs of adaptive introgression. The spatial distribution of genomic diversity and demographic reconstruction of the history of Tibetan sheep show a stepwise pattern of colonization with their initial spread onto the QTP from its northeastern part ∼3,100 years ago, followed by further southwest expansion to the central QTP ∼1,300 years ago. Together with archeological evidence, the date and route reveal the history of human expansions on the QTP by the Tang-Bo Ancient Road during the late Holocene. Our findings contribute to a depth understanding of early pastoralism and the local adaptation of Tibetan sheep as well as the late-Holocene human occupation of the QTP.

Chlorine injury enhances antibiotic resistance in Pseudomonas aeruginosa through over expression of drug efflux pumps

Adaption to adverse environments plays an important role in bacterial survival and is receiving increasing globe attention now. Here, cultivable chlorine-injured Pseudomonas aeruginosa, produced on the chlorination process, was investigated about their resistance to antibiotics. Then, global transcriptional analyses, quantitative PCR (qPCR) validation and antioxidant enzymes measurement were performed to explore the underlying mechanisms. The results showed that chlorine injury enhanced antibiotic resistance in P. aeruginosa and cultivable chlorine-injured P. aeruginosa exposed to 4 mg/L sodium hypochlorite (half of the lethal dose) improved antibiotic resistance against ceftazidime, chloramphenicol and ampicillin by 1.4-5.6 fold. This increase in antibiotic resistance was not hereditable and over expression of the MexEF-OprN efflux pump resulting from oxidative stress contributed to it. These results demonstrate temporal physiological persistence to antibiotics in cultivable chlorine-injured pathogens, suggesting their survival from adverse environments with antibiotic exposure and thereby posing lasting hazards to human health.

Profiling of intracellular and extracellular antibiotic resistance genes in tap water

Antibiotic resistance genes (ARGs) have gained global attention due to their public health threat. Extracelluar ARGs (eARGs) can result in the dissemination of antibiotic resistance via free-living ARGs in natural environments, where they promote ARB transmission in drinking water distribution systems. However, eARG pollution in tap water has not been well researched. In this study, concentrations of eARGs and intracellular ARGs (iARGs) in tap water, sampled at Tianjin, China, were investigated for one year. Fourteen eARG types were found at the highest concentration of 1.3 × 10⁵ gene copies (GC)/L. TetC was detected in 66.7% of samples, followed by sul1, sul2, and qnrA with the same detection frequency of 41.7%. Fifteen iARGs (including tetA, tetB, tetM, tetQ, tetX, sul1, sul2, sul3, ermB, blaTEM, and qnrA) were continuously detected in all collected tap water samples with sul1 and sul2 the most abundant. Additionally, both eARG and iARG concentrations in tap water presented a seasonal pattern with most abundant prevalence in summer. The concentration of observed intracellular sulfonamide resistance genes showed a significantly positive correlation with total nitrogen concentrations. This study suggested that eARG and iARG pollution of drinking water systems pose a potential risk to human public health.

Hepatitis C virus infection induces endoplasmic reticulum stress and apoptosis in human fetal liver stem cells

The cellular mechanisms by which hepatitis C virus (HCV) replication might mediate cytopathic effects are controversial and not entirely clear. In this study, we found that blood-borne HCV (bbHCV) infection could lead to endoplasmic reticulum (ER)-stress and mitochondria-related/caspase-dependent apoptosis at the early stages of infection based on use of the highly efficient bbHCV cell culture model established previously. Sections of bbHCV-infected human fetal liver stem cells (hFLSCs) revealed convolution and nonlinear ER, cell vacuolization, swelling of mitochondria, and numerous double membrane vesicles (DMVs). The percentage of apoptotic hFLSCs infected by bbHCV reached 29.8% at 16 h postinfection, and the amount of cytochrome c increased remarkably in the cytosolic protein fraction. However, over time, apoptosis was inhibited due to the activation of NF-κB. The expression of NF-κB-p65, Bcl-xL, XIAP, and c-FLIPL in hFLSCs was increased significantly 24 h after in infection by bbHCV. The accelerated cell death cycles involving apoptosis, regeneration and repair by bbHCV infection might give rise to the development of cirrhosis, and ultimately to hepatocellular carcinogenesis. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Chlorine disinfection increases both intracellular and extracellular antibiotic resistance genes in a full-scale wastewater treatment plant

The emergence and spread of antibiotic resistance has posed a major threat to both human health and environmental ecosystem. Although the disinfection has been proved to be efficient to control the occurrence of pathogens, little effort is dedicated to revealing potential impacts of disinfection on transmission of antibiotic resistance genes (ARGs), particularly for free-living ARGs in final disinfected effluent of urban wastewater treatment plants (UWWTP). Here, we investigated the effects of chlorine disinfection on the occurrence and concentration of both extracellular ARGs (eARGs) and intracellular ARGs (iARGs) in a full-scale UWWTP over a year. We reported that the concentrations of both eARGs and iARGs would be increased by the disinfection with chlorine dioxide (ClO₂). Specifically, chlorination preferentially increased the abundances of eARGs against macrolide (ermB), tetracycline (tetA, tetB and tetC), sulfonamide (sul1, sul2 and sul3), β-lactam (ampC), aminoglycosides (aph(2')-Id), rifampicin (katG) and vancomycin (vanA) up to 3.8 folds. Similarly, the abundances of iARGs were also increased up to 7.8 folds after chlorination. In terms of correlation analyses, the abundance of Escherichia coli before chlorination showed a strong positive correlation with the total eARG concentration, while lower temperature and higher ammonium concentration were assumed to be associated with the concentration of iARGs. This study suggests the chlorine disinfection could increase the abundances of both iARGs and eARGs, thereby posing risk of the dissemination of antibiotic resistance in environments.

Genome-Wide Association Analyses Highlight the Potential for Different Genetic Mechanisms for Litter Size Among Sheep Breeds

Reproduction is an important trait in sheep breeding as well as in other livestock. However, despite its importance the genetic mechanisms of litter size in domestic sheep (Ovis aries) are still poorly understood. To explore genetic mechanisms underlying the variation in litter size, we conducted multiple independent genome-wide association studies in five sheep breeds of high prolificacy (Wadi, Hu, Icelandic, Finnsheep, and Romanov) and one low prolificacy (Texel) using the Ovine Infinium HD BeadChip, respectively. We identified different sets of candidate genes associated with litter size in different breeds: BMPR1B, FBN1, and MMP2 in Wadi; GRIA2, SMAD1, and CTNNB1 in Hu; NCOA1 in Icelandic; INHBB, NF1, FLT1, PTGS2, and PLCB3 in Finnsheep; ESR2 in Romanov and ESR1, GHR, ETS1, MMP15, FLI1, and SPP1 in Texel. Further annotation of genes and bioinformatics analyses revealed that different biological pathways could be involved in the variation in litter size of females: hormone secretion (FSH and LH) in Wadi and Hu, placenta and embryonic lethality in Icelandic, folliculogenesis and LH signaling in Finnsheep, ovulation and preovulatory follicle maturation in Romanov, and estrogen and follicular growth in Texel. Taken together, our results provide new insights into the genetic mechanisms underlying the prolificacy trait in sheep and other mammals, suggesting targets for selection where the aim is to increase prolificacy in breeding projects.

Efficient replication of blood-borne hepatitis C virus in human fetal liver stem cells

The development of pathogenic mechanisms, specific antiviral treatments and preventive vaccines for hepatitis C virus (HCV) infection has been limited due to lack of cell culture models that can naturally imitate the entire HCV life cycle. Here, we established an HCV cell culture model based on human fetal liver stem cells (hFLSCs) that supports the entire blood-borne hepatitis C virus (bbHCV) life cycle. More than 90% of cells remained infected by various genotypes. bbHCV was efficiently propagated, and progeny virus were infectious to hFLSCs. The virus could be passed efficiently between cells. The viral infectivity was partially blocked by specific antibodies or small interfering RNA against HCV entry factors, whereas HCV replication was inhibited by antiviral drugs. We observed viral particles of approximately 55 nm in diameter in both cell culture media and infected cells after bbHCV infection.

CONCLUSION

Our data show that the entire bbHCV life cycle could be naturally imitated in hFLSCs. This model is expected to provide a powerful tool for exploring the process and the mechanism of bbHCV infection at the cellular level and for evaluating the treatment and preventive strategies of bbHCV infection. (Hepatology 2017;66:1045-1057).

Culture-dependent enumeration methods failed to simultaneously detect disinfectant-injured and genetically modified Escherichia coli in drinking water

Underestimation of Escherichia coli in drinking water, an indicator microorganism of sanitary risk, may result in potential risks of waterborne diseases. However, the detection of disinfectant-injured or genetically modified (GM) E. coli has been largely overlooked so far. To evaluate the accuracy of culture-dependent enumeration with regard to disinfectant-injured and GM E. coli, chlorine- or ozone-injured wild-type (WT) and GM E. coli were prepared and characterized. Then, water samples contaminated with these E. coli strains were assayed by four widely used methods, including lactose tryptose broth-based multiple-tube fermentation (MTF), m-endo-based membrane filtration method (MFM), an enzyme substrate test (EST) known as Colilert, and Petrifilm-based testing slip method (TSM). It was found that MTF was the most effective method to detect disinfectant-injured WT E. coli (with 76.9% trials detecting all these bacteria), while this method could not effectively detect GM E. coli (with uninjured bacteria undetectable and a maximal detection rate of 21.5% for the injured). The EST was the only method which enabled considerable enumeration of uninjured GM E. coli, with a detection rate of over 93%. However, the detection rate declined to lower than 45.4% once the GM E. coli was injured by disinfectants. The MFM was invalid for both disinfectant-injured and GM E. coli. This is the first study to report the failure of these commonly used enumeration methods to simultaneously detect disinfectant-injured and GM E. coli. Thus, it highlights the urgent requirement for the development of a more accurate and versatile enumeration method which allows the detection of disinfectant-injured and GM E. coli on the assessment of microbial quality of drinking water.

Shushe acids A-D from Ganoderma applanatum

Ganoderma applanatum is a fungus used for the prevention and treatment of a variety of disorders in China. In the present study, four new compounds, named shushe acids A-D (1-4), were isolated from the fruiting bodies of this species. Their structures were identified on the basis of spectroscopic methods. Compounds 1-4 are all natural product hybrids composed of derivatives of gallic acid, glycerol and succinic acid. None of the four compounds showed activity against the MCF-7 cell line.

Shushe Acids A-D from Ganoderma Applanatum

Ganoderma applanatum is a fungus used for the prevention and treatment of a variety of disorders in China. In the present study, four new compounds, named shushe acids A-D (1-4), were isolated from the fruiting bodies of this species. Their structures were identified on the basis of spectroscopic methods. Compounds 1-4 are all natural product hybrids composed of derivatives of gallic acid, glycerol and succinic acid. None of the four compounds showed activity against the MCF-7 cell line.

[Performance of Bio-zeolite Constructed Wetland in Dispersed Swine Wastewater Treatment]

The anaerobically digested effluent of the dispersed swine wastewater was treated by a three-stage bio-zeolite constructed wetland, and the performance of the wetland, the variation of pollutants concentration in effluent and ORP distribution in the bio-zeolite layer were studied. The results showed that COD, N and P in the digested effluent could be efficiently removed by the wetland, and the wetland also had resistance to ammonia impact load. When the hydraulic loading rate was 0.047 m³·(m²·d)^-1, COD, NH₄⁺-N and TN (the average mass concentrations in inflow were 477.7, 155.3 and 176.4 mg·L^-1) were mainly removed in the district 1 of the wetland, and the average removal rates were 80.6%, 55.3% and 58.1%, respectively. There was obvious enhancement of nitrification in the bio-zeolite, and the major nitrification product was nitrate. The mass concentrations of NO₃^--N in the district 1, district 2 and district 3 of the wetland were 85.85, 91.06 and 82.41 mg·L^-1, respectively. The nitrate produced in bio-zeolite layer of the district 1 could be denitrified by microorganisms in the slag brick layer using the residual organic substances in water as the substrate. TP was mainly removed by adsorption in the slag brick layer, and the role of microbe assimilation was relatively small. The reaeration of the bio-zeolite layer in the three-stage wetland was good. Most of the ORP values remained over 400 mV in the bio-zeolite layer.

Whole-Genome Sequencing of Native Sheep Provides Insights into Rapid Adaptations to Extreme Environments

Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8–9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of ∼5× for 75 samples and ∼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (<100 m), high-altitude region (>1500 m) versus low-altitude region (<1300 m), desert (<10 mm average annual precipitation) versus highly humid region (>600 mm), and arid zone (<400 mm) versus humid zone (>400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change.

A new adsorption-elution technique for the concentration of aquatic extracellular antibiotic resistance genes from large volumes of water

Extracellular antibiotic resistance genes (eARGs) that help in the transmission and spread of antibiotic-resistant bacteria are emerging environmental contaminants in water, and there is therefore a growing need to assess environmental levels and associated risks of eARGs. However, as they are present in low amounts, it is difficult to detect eARGs in water directly with PCR techniques. Here, we prepared a new type of nucleic acid adsorption particle (NAAP) with high capacity and developed an optimal adsorption-elution method to concentrate eARGs from large volumes of water. With this technique, we were able to achieve an eARG recovery rate of above 95% from 10 L of water samples. Moreover, combining this new method with quantitative real-time PCR (qPCR), the sensitivity of the eARG detection was 10(4) times that of single qPCR, with the detection limit lowered to 100 gene copies (GCs)/L. Our analyses showed that the eARG load, virus load and certain water characteristics such as pH, chemical oxygen demand (CODMn), and turbidity affected the eARGs recovery rate. However, high eARGs recovery rates always remained within the standard limits for natural surface water quality, while eARG levels in water were lower than the detection limits of single qPCR assays. The recovery rates were not affected by water temperature and heterotrophic plate counts (HPC). The eARGs whatever located in the plasmids or the short-length linear DNAs can be recovered from the water. Furthermore, the recovery rate was high even in the presence of high concentrations of plasmids in different natural water (Haihe river, well water, raw water for drinking water, Jinhe river, Tuanbo lake and the Yunqiao reservoir). By this technology, eARGs concentrations were found ranging from (2.70 ± 0.73) × 10(2) to (4.58 ± 0.47) × 10(4) GCs/L for the extracellular ampicillin resistance gene and (5.43 ± 0.41) × 10(2) to (2.14 ± 0.23) × 10(4) GCs/L for the extracellular gentamicin resistance gene in natural water for the first time, respectively. All these findings suggest that NAAPs have great potential for the monitoring of eARGs pollution in water.

Mitogenomic Meta-Analysis Identifies Two Phases of Migration in the History of Eastern Eurasian Sheep

Despite much attention, history of sheep (Ovis aries) evolution, including its dating, demographic trajectory and geographic spread, remains controversial. To address these questions, we generated 45 complete and 875 partial mitogenomic sequences, and performed a meta-analysis of these and published ovine mitochondrial DNA sequences (n = 3,229) across Eurasia. We inferred that O. orientalis and O. musimon share the most recent female ancestor with O. aries at approximately 0.790 Ma (95% CI: 0.637-0.934 Ma) during the Middle Pleistocene, substantially predating the domestication event (∼8-11 ka). By reconstructing historical variations in effective population size, we found evidence of a rapid population increase approximately 20-60 ka, immediately before the Last Glacial Maximum. Analyses of lineage expansions showed two sheep migratory waves at approximately 4.5-6.8 ka (lineages A and B: ∼6.4-6.8 ka; C: ∼4.5 ka) across eastern Eurasia, which could have been influenced by prehistoric West-East commercial trade and deliberate mating of domestic and wild sheep, respectively. A continent-scale examination of lineage diversity and approximate Bayesian computation analyses indicated that the Mongolian Plateau region was a secondary center of dispersal, acting as a "transportation hub" in eastern Eurasia: Sheep from the Middle Eastern domestication center were inferred to have migrated through the Caucasus and Central Asia, and arrived in North and Southwest China (lineages A, B, and C) and the Indian subcontinent (lineages B and C) through this region. Our results provide new insights into sheep domestication, particularly with respect to origins and migrations to and from eastern Eurasia.

[Denitrification performance of PBS as a solid carbon source of denitrification]

Poly-butylenes succinate (PBS) was used as solid denitrification carbon source and biofilm carrier, to investigate the denitrification performance and the influence of adding inert carrier. The experimental results showed that PBS could serve as solid carbon source for denitrification of low C/N ratio wastewater, but the startup time was longer, about 33 d. There was no accumulation of nitrite nitrogen in the process of denitrification, but it produced less than 0.8 mg x L(-1) ammonia nitrogen. Increasing the amount of biofilm in PBS supported denitrification system by adding the inert carrier could improve the denitrification rate. The denitrification rates of PBS, PBS + 30 g gravel, PBS + 60 g gravel and PBS +90 g gravel systems were 5.33, 7.04, 10.05 and 6.93 mg x (L x h)(-1), respectively, and all reactions were zero order. During the denitrification process (0-9 h), DOC increased before it was reduced. At the end of the denitrification reaction (24 h), DOC of the denitrification system with inert carrier 60 g gravel and 90 g gravel was 16.34 mg x L(-1) and 19.22 mg x L(-1), respectively, higher than that without gravel of 13.48 mg x L(-1). The pH of all denitrification systems were lower than the initial value, which was the result of comprehensive function of acidic substances and alkalinity produced in the process of degradation of solid carbon source and denitrification, respectively.

Seroprevalence and evolutionary dynamics of genotype 4 hepatitis E virus in Shandong Province, China

AIM: To investigate the seroprevalence and evolutionary dynamics of hepatitis E virus (HEV) and assess the ancestor of HEVs in China’s Shandong Province.

METHODS: A total of 2028 serum, 60 fecal and 82 bile samples were collected from the general human population, patients and swine, respectively. This seroepidemiological study was conducted using an immunnosorbent assay and HEV RNA was detected by the reverse transcription-nested polymerase chain reaction (RT-nPCR) method. Complete genome sequences of the prevalent strains (CH-YT-HEV01, CH-YT-HEV02 and CH-YT-sHEV01) were determined, and the sequences were analyzed phylogenetically. In addition, the evolutionary dynamics of three HEV isolates were determined using the framework of coalescent analysis in the program package BEAST, and the time of the most recent common ancestors (TMRCAs) of China-indigenous genotype 4 HEV isolates was calculated.

RESULTS: The overall viral burden in the general human population was 0.1%, and the positive rates of anti-HEV IgG and IgM in the serum specimens were 25.1% (509/2028) and 2.3% (51/2028), respectively. In addition, IgG positivity increased with age. The phylogenetic analysis based on the full-length nucleotide sequences showed that the strain CH-YT-HEV02 was directly related to CH-YT-sHEV01 with a 94% identity, suggesting that they were involved in cross-species transmission. The isolate CH-YT-HEV01 was close to HB-3 and CHN-SD-sHEV with a bootstrap value of 100%, sharing a 96.1%-96.4% identity with each other. Surprisingly, the HB-3 strain was a representative strain prevalent in swine in Hubei, and the isolate CHN-SD-sHEV was obtained from swine in Shandong in a previous report. TMRCA for the clade of CH-YT-HEV01 and HB-3 was 2003, which was consistent with the TMRCA for the clade of CHN-SD-sHEV and HB-3, and they were both earlier than the TMRCA for the clade of CH-YT-HEV01 and CHN-SD-sHEV (2004).

CONCLUSION: The strains CH-YT-HEV01, CHN-SD-sHEV and HB-3 are involved in trans-regional transmission, and the ancestors of HEVs in Shandong come from Hubei Province.

Development of a novel filter cartridge system with electropositive granule media to concentrate viruses from large volumes of natural surface water

Exposure to various infectious viruses in environmental drinking water can constitute a public health risk. However, it is difficult to detect viruses in water due to their low concentration. In this study, we have developed a novel filter cartridge system containing electropositive granule media (EGM). Viruses present in large volumes of environmental samples were adsorbed onto the EGM, and then recovered by elution and poly(ethylene glycol) (PEG) concentration. To evaluate the system's efficiency in viral recovery, poliovirus (PV-1), a surrogate for enteric viruses, was used to artificially contaminate river water samples which were then assayed by quantitative real-time PCR. To optimize the concentration procedure, the eluent type, water flow rate and properties (e.g., pH, bacterial, and viral loads), were evaluated. The highest virus recovery was obtained by pumping river water at a flow rate of 300 mL/min and then pushing 3 L of an eluent containing 3× broth [1.5% (w/v) NaCl, 3% (w/v) tryptone, 1.5% (w/v) beef powder] with 0.05 mol/L glycine through the filter. Using this procedure, the recovery efficiencies of PV-1 from 10 to 100 L of spiked river water were up to 99%. In addition, this method is virus load and pH dependent. Virus recovery was maximal at a load of between 10(3.5) and 10(5.5) TCID50 and a pH ranging from 5 to 7. The bacterial load in the water has no effect on virus recovery. Different types of viruses and surface water were tested to validate the system's applicability. Results revealed that the EGM filter cartridge was able to concentrate PV-1, human adenoviruses (HAdVs) and noroviruses (HuNoVs) with high efficiency from river, lake, and reservoir water. Furthermore, it showed more efficient recovery than glass wool and 1MDS filters. These data suggest that this system provides rapid and efficient virus recovery from a large volume of natural surface water and, as such, could be a useful tool in revealing the presence of viruses in surface water.

Resumption of menstruation and pituitary response to gonadotropin-releasing hormone in functional hypothalamic amenorrhea subjects undertaking estrogen replacement therapy

BACKGROUND

Functional hypothalamic amenorrhea (FHA) refers to a functional menstrual disorder with various causes and presentations. Recovery of menstrual cyclicity is common in long-term follow-up but the affecting factors remain unknown.

AIM

To explore factors affecting the menstrual resumption and to evaluate the pituitary response to gonadotropin-releasing hormone (GnRH) in FHA.

MATERIALS AND METHODS

Thirty cases with FHA were recruited. All subjects were put on continuous 1 mg/day estradiol valerate orally and followed up monthly. Recovery was defined as the occurrence of at least three consecutive regular cycles. Responder referred to those who recovered within two years of therapy. Gonadotropin response to the 50 μg GnRH challenge was tested every three months.

RESULTS

Nineteen (63.3%) subjects recovered with a mean time to recovery of 26.8 months. Time to recovery was negatively correlated with body mass index (BMI) before and by amenorrhea. Twentyone cases had undertaken therapy for more than two years and 10 of them recovered. BMI before and by amenorrhea were negatively correlated with the recovery. Significant increase of serum luteinizing hormone (LH) and LH response to GnRH were noted after recovery.

CONCLUSIONS

Menstrual resumption was common in FHA undertaking estrogen replacement therapy (ERT). The likelihood of recovery was affected by their BMI before and by amenorrhea but not by the weight gain during therapy. Low serum LH and attenuated LH response to GnRH were the main features of pituitary deficiency in FHA. The menstrual resumption in FHA was accompanied by the recovery of serum LH and the LH response to GnRH.

[Determination of chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco by Fourier transform near infrared spectroscopy]

The objective of the present study was to investigate the feasibility of predicting chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco by Fourier transform near-infrared (FT-NIR) spectroscopy. The partial least squares(PLS) regression method, second derivative and Norris derivative filter were applied in the NIR spectroscopy prediction of chlorogenic acid, rutin, scopoletin and total polyphenol in the range of 7 500 to 4 000 cm(-1). For chlorogenic acid, rutin, scopoletin and total polyphenol, the determination coefficients were 0.976 6, 0.941 9, 0.957 1 and 0.966 6, respectively. The SEP/SEC values for them were < 1.2, and the SD/SEP values for them were > 2. The root mean square error of cross validation (RMSECV) of the four calibration models were 1.938 9, 1.046 2, 0.047 9 and 2.745 2, respectively. NIR spectroscopy was compared with the conventional methods. The results show that the two methods showed no significant difference at the significant level of 0.05. NIR spectroscopy technology can accurately analyze chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco.

Strategy for pH control and pH feedback-controlled substrate feeding for high-level production of L-tryptophan by Escherichia coli

Optimum production of L-tryptophan by Escherichia coli depends on pH. Here, we established conditions for optimizing the production of L-tryptophan. The optimum pH range was 6.5-7.2, and pH was controlled using a three-stage strategy [pH 6.5 (0-12 h), pH 6.8 (12-24 h), and pH 7.2 (24-38 h)]. Specifically, ammonium hydroxide was used to adjust pH during the initial 24 h, and potassium hydroxide and ammonium hydroxide (1:2, v/v) were used to adjust pH during 24-38 h. Under these conditions, NH4 (+) and K(+) concentrations were kept below the threshold for inhibiting L-tryptophan production. Optimization was also accomplished using ratios (v/v) of glucose to alkali solutions equal to 4:1 (5-24 h) and 6:1 (24-38 h). The concentration of glucose and the pH were controlled by adjusting the pH automatically. Applying a pH-feedback feeding method, the steady-state concentration of glucose was maintained at approximately 0.2 ± 0.02 g/l, and acetic acid accumulated to a concentration of 1.15 ± 0.03 g/l, and the plasmid stability was 98 ± 0.5 %. The final, optimized concentration of L-tryptophan was 43.65 ± 0.29 g/l from 52.43 ± 0.38 g/l dry cell weight.

A survey of drug resistance bla genes originating from synthetic plasmid vectors in six Chinese rivers

Antibiotic resistance poses a significant challenge to human health and its rate continues to rise globally. While antibiotic-selectable synthetic plasmid vectors have proved invaluable tools of genetic engineering, this class of artificial recombinant DNA sequences with high expression of antibiotic resistance genes presents an unknown risk beyond the laboratory setting. Contamination of environmental microbes with synthetic plasmid vector-sourced antibiotic resistance genes may represent a yet unrecognized source of antibiotic resistance. In this study, PCR and real-time quantitative PCR were used to investigate the synthetic plasmid vector-originated ampicillin resistance gene, β-lactam antibiotic (blá), in microbes from six Chinese rivers with significant human interactions. Various levels of blá were detected in all six rivers, with the highest levels in the Pearl and Haihe rivers. To validate the blá pollution, environmental plasmids in the river samples were captured by the E. coli transformants from the community plasmid metagenome. The resultant plasmid library of 205 ampicillin-resistant E. coli (transformants) showed a blá-positive rate of 27.3% by PCR. Sequencing results confirmed the synthetic plasmid vector sources. In addition, results of the Kirby-Bauer disc-diffusion test reinforced the ampicillin-resistant functions of the environmental plasmids. The resistance spectrum of transformants from the Pearl and Haihe rivers, in particular, had expanded to the third- and fourth-generation of cephalosporin drugs, while that of other transformants mainly involved first- and second-generation cephalosporins. This study not only reveals environmental contamination of synthetic plasmid vector-sourced blá drug resistance genes in Chinese rivers, but also suggests that synthetic plasmid vectors may represent a source of antibiotic resistance in humans.

[Advance in immunology and immune evasion of PRRSV]

Porcine reproductive and respiratory syndrome virus (PRRSV) continues to be a threat, causing economically significant impacts on the swine industry worldwide. Unfortunately, the traditional control strategies and conventional vaccines fail to provide sustainable disease control, in particular against genetically diverse strains, as they suffer from both antigenic heterogeneity and various immune evasion strategies of PRRSV. In this paper, latest research progress in immunology and immune evasion of PRRSVis summarized to provide a referenc for PRSSV prevention and control as well as the design of new vaccines.

The 40-80 nt region in the 5'-NCR of genome is a critical target for inactivating poliovirus by chlorine dioxide

Chemical disinfection is the most common method used to inactivate viruses from drinking water throughout the world. In this study, cell culture, ELISA, RT-PCR, and spot hybridization were employed to investigate the mechanism underlying chlorine dioxide (ClO(2) )-induced inactivation of Poliovirus type 1 (PV1), which was also confirmed by recombinant viral genome RNA infection models. The results suggested that ClO(2) inactivated PV1 primarily by disrupting the 5'-non-coding region (5'-NCR) of the PV1 genome. Further study revealed that ClO(2) degraded specifically the 40-80 nucleotides (nt) region in the 5'-NCR. Recombinant viral genome RNA infection models confirmed that PV1 RNA lacking this 40-80 nt region was not infectious. This study not only elucidated the mechanism of PV1 inactivation by ClO(2), but also defined the critical genetic target for the disinfectant to inactivate Poliovirus. This study also provides a strategy by which rapid, accurate, and molecular methods based on sensitive genetic targets may be established for evaluating the effects of disinfectants on viruses.

[Screening of the aerobic simultaneous denitrobacteria and its denitrification characteristics]

To screen aerobic heterotrophic denitrifying bacteria from various samples and detect metabolites quantitatively during their denitrification process. The bacteria were screened by limit dilution and crossed separation. Nitrate and nitrite were determined using phenol disulfonic acid and N-(1-naphthyl)-ethylene diamine by ultraviolet spectrophotometry. The N2 was detected by gas chromatography. Six aerobic heterotrophic bacteria were isolated and YY-5 was demonstrated to be the greatest denitrifer. The degradation rate of its hydroxylamine oxidoreductase can reached to 70.9%. Above all, there is a good balance between the removal of total nitrogen and production of N2 in process. No N2O was produced and no nitrate or nitrite were accumulated. The high ability of aerobic heterotrophic bacterium YY-5 for denitrification was screened, which showed higher homology with Acinetobacter genus through 16S rRNA blast.

Vitamin E modulates cigarette smoke extract-induced cell apoptosis in mouse embryonic cells

Vitamin E (VE) can effectively prevent occurrence of lung cancer caused by passive smoking in mice. However, whether VE prevents smoking-induced cytotoxicity remains unclear. In this study, a primary culture of embryonic lung cells (ELCs) was used to observe the cytotoxic effects of cigarette smoke extract (CSE), including its influence on cell survival, cell cycle, apoptosis, and DNA damage, and also to examine the effects of VE intervention on CSE-induced cytotoxicity. Our results showed that CSE could significantly inhibit the survival of ELCs with dose- and time-dependent effects. Furthermore, CSE clearly disturbed the cell cycle of ELCs by decreasing the proportion of cells at the S and G₂/M phases and increasing the proportion of cells at the G₀/G₁ phase. CSE promoted cell apoptosis, with the highest apoptosis rate reaching more than 40%. CSE also significantly caused DNA damage of ELCs. VE supplementation could evidently inhibit or reverse the cytotoxic effects of CSE in a dose- and time-dependent manner. The mechanism of CSE effects on ELCs and that of VE intervention might involve the mitochondrial pathway of cytochrome c-mediated caspase activation. Our study validate that VE plays a clearly protective effect against CSE-induced cytotoxicity in mouse embryonic lung cells.

Estrogen promotes benzo[a]pyrene-induced lung carcinogenesis through oxidative stress damage and cytochrome c-mediated caspase-3 activation pathways in female mice

Estrogen may contribute to the development of smoking-induced lung cancer in women. To test this hypothesis, an mouse model was used to investigate the effects of 17 beta-estradiol (E2) on benzo[a]pyrene (B[a]P)-induced lung carcinogenesis. We found that B[a]P could cause oxidative stress damage, upregulate mitochondrial cytochrome-c and caspase-3 expression, induce lung carcinogenesis in female mice, E2 promoted these effects of B[a]P while tamoxifen (TAM) inhibited this effects of E2. We conclude that E2 can promote the tumorigenic effects of B[a]P in female mice, and oxidative stress damage and activation of cytochrome-c-mediated caspase-3 pathway may be involved in this process.

[Rapid method to extract high-quality RNA from activated sludge]

An effective and fast RNA isolation method of activated sludge was established and five different methods were compared based on RNA yield, purity, integrity, RT-PCR amplification of 16S rRNA genes and subsequent terminal restriction fragment length polymorphism (T-RFLP) analysis. That is, the precipitated activated sludge was washed with TENP and PBS buffer, followed by using lysozyme and TRIzol to direct lysis of microbial cells, chloroform to remove protein and most of the DNA from bacterial lysate, isopropanol to precipitate nucleic acid and DNase I to hydrolyze residual DNA. To further purify RNA, RNA purifying column was utilized. The results demonstrated that the extraction method, with the aid of TRIzol and RNA purification kit, can effectively extract high-quality RNA. It not only means low degradability and high quantity, purity and diversity, but also the genes of 16S rRNA and amoA can be amplified by RT-PCR. Compared with other methods, it showed great advantage of low cost and high efficiency and can be applied to RNA extraction of activated sludge in a large number. Furthermore, T-RFLP results indicated that the community composition as well as the abundance of individual members was affected by the kind of RNA extraction methods. This work established a rapid and effective method to extract high-quality RNA from activated sludge and would show great potential for monitoring microbial changes and studying metabolism and community array of activated sludge.

Effects of copper-aspirin complex on plasma 6-keto-prostaglandin F1αlevel and platelet cytosolic calcium in rabbits

Effects of copper-aspirin complex on washed platelet aggregation, thromboxane B(2) formation and 6-ketoprostaglandin F(1alpha) level were monitored by Born's and Terashita's methods, respectively. The influence of copper-aspirin complex on cytosolic free calcium was examined using the fluorescent indicator, Fura 2-AM. Copper-aspirin complex significantly inhibited arachidonic acid-induced aggregation in washed platelets. The IC(50) value was 9.6 micromol L(-1). Copper-aspirin complex significantly decreased arachidonic acid-induced thromboxane B(2) formation by 87.1% in washed platelets. Ten mg kg(-1) of copper-aspirin complex given intragastrically markedly increased the plasma level of 6-keto-prostaglandin F(1alpha). Aspirin, however, reduced both thromboxane B(2) formation and 6-keto-prostaglandin F(1alpha) level. In the presence of CaCl2 1 mmol L(-1), copper-aspirin complex (20, 40 and 80 micromol L(-1)) markedly lowered arachidonic acid-induced increase in platelet calcium from the resting level (270+/-36 nmol L(-1)) to 213+/-14, 170+/-20 and 135+/-17 nmol L(-1), respectively. In the presence of ethylene glycol-bis (beta-aminoethyl ether) N,N,N',N'-tetraacetic acid 1 mmol L(-1), copper-aspirin complex (20, 40 and 80 micromol l L(-1)) significantly suppressed the release of intracellular calcium induced by arachidonic acid from 127+/-23 nmol L-1 to 108+/-17, 93+/-12 and 70+/-13 nmol L(-1).

Antioxidant intervention of smoking-induced lung tumor in mice by vitamin E and quercetin

Background

Epidemiological and in vitro studies suggest that antioxidants such as quercetin and vitamin E (VE) can prevent lung tumor caused by smoking; however, there is limited evidence from animal studies.

Methods

In the present study, Swiss mouse was used to examine the potential of quercetin and VE for prevention lung tumor induced by smoking.

Results

Our results suggest that the incidence of lung tumor and tumor multiplicity were 43.5% and 1.00 ± 0.29 in smoking group; Quercetin has limited effects on lung tumor prevention in this in vivo model, as measured by assays for free radical scavenging, reduction of smoke-induced DNA damage and inhibition of apoptosis. On the other hand, vitamin E drastically decreased the incidence of lung tumor and tumor multiplicity which were 17.0% and 0.32 ± 0.16, respectively (p < 0.05); and demonstrated prominent antioxidant effects, reduction of DNA damage and decreased cell apoptosis (p < 0.05). Combined treatment with quercetin and VE in this animal model did not demonstrate any effect greater than that due to vitamin E alone. In addition, gender differences in the occurrence of smoke induced-lung tumor and antioxidant intervention were also observed.

Conclusion

We conclude that VE might prevent lung tumor induced by smoking in Swiss mice.

Impacts of passive smoking on learning and memory ability of mouse offsprings and intervention by antioxidants

OBJECTIVE

To determine the impact of passive smoking and the protective effect of antioxidants such as vitamin E and quercetin on learning and memory ability of mouse offsprings.

METHODS

A passive smoking model of pregnant mice was established. Learning and memory ability was evaluated by the water maze test and long term potentiation (LTP). Nitric oxide (NO), content, nitric oxide synthase (NOS), acetylcholinesteras (Ache) activity in brain, vitamin E concentration, and reactive oxygen species (ROS) in serum were determined. The latency period (the time during which the mice swim from the starting position to the ending position) and errors (the number of mice entering the blind end) in control and antioxidant intervention groups were compared with those in the smoke exposure group after 6 days.

RESULTS

The latency period as well as errors in the air, control diet, tobacco smoke (TS), and vitamin E diet groups were decreased significantly as compared with the TS and control diet groups (P<0.05). LTP was restrained in the TS and control diet groups. LTP in all the antioxidant diet groups was significantly increased compared with the TS and control diet groups. In addition, NOS and acetylcholinesteras (Ache) activitiy was significantly higher in the TS and control diet groups than in the air and control diet group. NO content was not significantly different among the different groups, and significantly lower in the TS and vitamin E diet groups than in the TS group, control diet group, quercetin diet group, and mixture diet group (P<0.05). Vitamin E concentration and ROS activity in serum were correlated with the outcome of water maze and LTP.

CONCLUSION

Passive smoking reduces LTP formation by disturbing the hippocampus function of mice, by decreasing NOS and Ache activity and increasing NO content. Antioxidants (especially vitamin E) partially improve the learning and memory ability of offsprings whose mothers are exposed to tobacco smoke during pregnancy.

Isolation, identification and function of a novel anti-HSV-1 protein from Grifola frondosa

A novel antiviral protein was purified from an extract of Grifola frondosa fruiting bodies using a procedure that included 40% ammonium sulfate precipitation and DEAE-cellulose ion exchange chromatography, and designated GFAHP. This protein inhibited herpes simplex virus type 1 (HSV-1) replication in vitro with an IC(50) value of 4.1 microg/ml and a therapeutic index >29.3. Higher concentrations of GFAHP (125 and 500 microg/ml) also significantly reduced the severity of HSV-1 induced blepharitis, neovascularization, and stromal keratitis in a murine model. Topical administration of GFAHP to the mouse cornea resulted in a significant decrease in virus production (mean virus yields: 3.4log10PFU in the treated group and 4.19log10PFU in the control group). We proved that GFAHP directly inactivates HSV-1 while simultaneously inhibiting HSV-1 penetration into Vero cells. Gel electrophoresis showed that GFAHP had a molecular weight of 29.5 kDa. GFAHP was tryptic digested and analyzed from the PMF of matrix assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and nanoelectrospray ionization tandem mass spectrometry. The N-terminal sequence of GFAHP consisted of an 11 amino acid peptide, NH(2)-REQDNAPCGLN-COOH that did not match any known amino acid sequences, indicating that GFAHP is likely to be a novel antivirus protein. To our knowledge, this is the first report that characterizes an anti-HSV protein from G. frondosa.

Development and application of an oligonucleotide microarray for the detection of food-borne bacterial pathogens

The rapid and accurate detection and identification of food-borne pathogenic bacteria is critical for food safety. In this paper, we describe a rapid (<4 h) high-throughput detection and identification system that uses universal polymerase chain reaction (PCR) primers to amplify a variable region of bacterial the 16S rRNA gene, followed by reverse hybridization of the products to species-specific oligonucleotide probes on a chip. This procedure was successful in discriminating 204 strains of bacteria from pure culture belonging to 13 genera of bacteria. When this method was applied directly to 115 strains of bacteria isolated from foods, 112/115 (97.4%) were correctly identified; two strains were indistinguishable due to weak signal, while one failed to produce a PCR product. The array was used to detect and successfully identify two strains of bacteria from food poisoning outbreak samples, giving results through hybridization that were identical to those obtained by traditional methods. The sensitivity of the microarray assay was 10(2) CFU of bacteria. Thus, the oligonucleotide microarray is a powerful tool for the detection and identification of pathogens from foods.

High-throughput identification of clinical pathogenic fungi by hybridization to an oligonucleotide microarray

Here we report the development of an oligonucleotide microarray method that can identify fungal pathogens in a single reaction. Specific oligonucleotide probes targeted to internal transcribed spacer 2 were designed and synthesized. Fungal DNA was amplified by universal primers, and the PCR product was hybridized with the oligonucleotide microarray. A series of specific hybridization profiles corresponding to species were obtained. The 122 strains of fungal pathogens, including standard and clinically isolated strains, used to test the specificity, stability, and sensitivity of the microarray system belonged to 20 species representing 8 genera. We found that the microarray system can successfully discriminate among the fungal pathogens to the species level, with high specificity and stability. The sensitivity was 15 pg/ml of DNA. This oligonucleotide microarray system represents a rapid, simple, and reliable alternative to conventional methods of identifying common clinical fungal isolates.

In vitro screening of traditionally used medicinal plants in China against Enteroviruses

AIM: To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents.

METHODS: The aqueous extracts (AE) of more than 100 traditionally used medicinal plants in China were evaluated for their In vitro anti-Coxsackie virus B3 activities with a MTT-based colorimetric assay.

RESULTS: The test for AE of 16 plants exhibited anti-Coxsackie virus B3 activities at different magnitudes of potency. They can inhibit three steps (inactivation, adsorption and replication) during the infection. Among the 16 plants, Sargentodoxa cuneata (Oliv.) Rehd. et Wils., Sophora tonkinensis Gapnep., Paeonia veitchii Lynch, Spatholobus suberectus Dunn. and Cyrtomium fortunei J. sm. also have activity against other enterovirus, including Coxsackie virus B5, Polio virus I, Echo virus 9 and Echo virus 29. Cell cytotoxic assay demonstrated that all tested AE had CC₅₀ values higher than their EC₅₀ values.

CONCLUSION: The sixteen traditionally used medicinal plants in China possessed antiviral activity, and some of them merit further investigations.