The key sulfometuron-methyl degrading bacteria isolation based on soil bacterial phylogenetic molecular ecological networks and application for bioremediation of contaminated soil by immobilization.

The analysis of soil bacterial community has guiding significance for fully utilization of soil microbial resources. The results of high-throughput sequencing (HTS) showed that the bacteria in the three sulfometuron-methyl contaminated soil samples were mainly composed of 677 genera, including Phenylobacterium, Bacillus, belonging to 28 phyla, including Proteobacteria, Firmicutes. The diversity and richness of bacterial community decreased with the increase in sulfometuron-methyl concentration. In addition, sulfometuron-methyl could also affect the soil bacterial function based on PICRUSt functional predictive analysis. Combined with the results of HTS and phylogenetic molecular ecological networks (pMENs), 12 genera, including Ralstonia (Pi=0.64), were identified as the key soil microflora (intra-module connectivity Zi ≥ 2.5 or inter-module connectivity Pi ≥ 0.62), and the abundance of Ralstonia significantly increased with the concentration of sulfometuron-methyl, indicating that the strains of this genus might be the potential degrading bacteria and could form a stable relationship with indigenous microorganisms. Among the isolated bacteria of genus Ralstonia, one strain, named Ralstonia sp. JM-1, was verified to possess higher sulfometuron-methyl degradation efficiency, which completely degraded 20 mg L-1 of sulfometuron-methyl within 96 h. Furthermore, the immobilized strains generated by the mixture of 2.0 g bamboo charcoal and 3.0 mL bacterial suspension for 24 h had the highest sulfometuron-methyl degradation rate than that under other conditions, and the dynamic process degrading 10-30 mg L-1 of sulfometuron-methyl conforms to the zero-order kinetic equation. The bioremediation of contaminated soil showed the immobilized strains could completely degrade sulfometuron-methyl (1.39 mg kg-1) in contaminated soil within 9 d, which is higher than that application of strains in the free state (74.8%). This study could provide ideas for the isolation of functional strains and a theoretical basis for the bioremediation of STM and other contaminated soils.

Chemical Constituents of the Deep-Sea-Derived Fungus Cladosporium oxysporum 170103 and Their Antibacterial Effects.

The Cladosporium fungi, one of the largest genera of dematiaceous hyphomycetes, could produce various bioactive secondary metabolites. From the AcOEt-soluble extract of Cladosporium oxysporum 170103, three new secopatulolides (1-3) and thirteen known compounds (4-16) were obtained. Their structures were established by detailed analysis of the NMR and HR-ESI-MS data. All sixteen compounds were tested for antibacterial activity against Vibrio parahemolyticus, ergosterol (10) presented moderate effect with the minimum inhibitory concentration (MIC) of 32 µM. It can destruct the membrane integrity of Vibrio parahemolyticus to change the cell shape.

Tracing aquatic bioavailable Hg in three different regions of China using fish Hg isotopes.

To trace the most concerned bioavailable mercury (Hg) in aquatic environment, fish samples were collected from three typical regions in China, including 3 rivers and 1 lake in the Tibetan Plateau (TP, a high altitude background region with strong solar radiation), the Three Gorges Reservoir (TGR, the largest artificial freshwater reservoir in China), and the Chinese Bohai Sea (CBS, a heavily human-impacted semi-enclosed sea). The Hg isotopic compositions in fish muscles were analyzed. The results showed that anthropogenic emissions were the main sources of Hg in fish from TGR and CBS because of the observed negative δ202Hg and positive Δ199Hg in these two regions (TGR, δ202Hg: - 0.72 to - 0.29‰, Δ199Hg: 0.15 - 0.52‰; CBS, δ202Hg: - 2.09 to - 0.86‰, Δ199Hg: 0.07 - 0.52‰). The relatively higher δ202Hg and Δ199Hg (δ202Hg: - 0.37 - 0.08‰, Δ199Hg: 0.50 - 1.89‰) in fish from TP suggested the insignificant disturbance from local anthropogenic activities. The larger slopes of Δ199Hg/Δ201Hg in fish from TGR (1.29 ± 0.14, 1SD) and TP (1.25 ± 0.06, 1SD) indicated methylmercury (MeHg) was produced and photo-reduced in the water column before incorporation into the fish. In contrast, the photoreduction of Hg2+ was the main process in CBS (slope of Δ199Hg/Δ201Hg: 1.06 ± 0.06, 1SD). According to the fingerprint data of Hg isotopes, the most important source for aquatic bioavailable Hg in TP should be the long-range transported Hg, contrasting to the anthropogenic originated MeHg from surface sediments and runoffs in TGR and inorganic Hg from continental inputs in CBS. Therefore, the isotopic signatures of Hg in fish can provide novel clues in tracing sources and behaviors of bioavailable Hg in aquatic systems, which are critical for further understanding the biogeochemical cycling of Hg.

Mutual detoxification of mercury and selenium in unicellular Tetrahymena.

Selenium (Se) is commonly recognized as a protective element with an antagonistic effect against mercury (Hg) toxicity. However, the mechanisms of this Hg-Se antagonism are complex and remain controversial. To gain insight into the Hg-Se antagonism, a type of unicellular eukaryotic protozoa (Tetrahymena malaccensis, T. malaccensis) was selected and individually or jointly exposed to two Hg and three Se species. We found that Se species showed different toxic effects on the proliferation of T. malaccensis with the toxicity following the order: selenite (Se(IV))>selenomethionine (SeMeth)>selenate (Se(VI)). The Hg-Se antagonism in Tetrahymena was observed because the joint toxicity significantly decreased under co-exposure to highly toxic dosages of Hg and Se versus individual toxicity. Unlike Se(IV) and Se(VI), non-toxic dosage of SeMeth significantly decreased the Hg toxicity, revealing the influence of the Se species and dosages on the Hg-Se antagonism. Unexpectedly, inorganic divalent Hg (Hg2+) and monomethylmercury (MeHg) also displayed detoxification towards extremely highly toxic dosages of Se, although their detoxifying efficiency was discrepant. These results suggested mutual Hg-Se detoxification in T. malaccensis, which was highly dependent on the dosages and species of both elements. As compared to other species, SeMeth and MeHg promoted the Hg-Se joint effects to a higher degree. Additionally, the Hg contents decreased for all the Hg-Se co-exposed groups, revealing a sequestering effect of Se towards Hg in T. malaccensis.

Reaction of antibiotic sulfadiazine with manganese dioxide in aqueous phase: Kinetics, pathways and toxicity assessment.

Sulfonamide antibiotics are often detected in terrestrial and aquatic environment, but little is known about abiotic degradation of these antibiotics. In the present study, the degradation of the sulfonamide antibiotic sulfadiazine by a synthesized δ-MnO2 was investigated. The initial reaction rate of sulfadiazine oxidized by manganese dioxide increased as the solution pH decreased by weakening electrostatic attraction between sulfadiazine and MnO2 and enhancing the reduction potential of MnO2. The presence of metal ions (Mn2+, Na+ and Ca2+), especially Mn2+, decreased the initial reaction rate by competitively adsorbing and reacting with MnO2. Two different products were identified during the reaction of sulfadiazine with MnO2 and the transformation of parent compound started with the formation of sulfadiazine radicals. Furthermore, toxicity assay results showed that the toxicity of products produced by bacteria decreased with elapse of reaction time. Results from the present study indicate that manganese dioxides in environmental matrix could be helpful in dissipation of sulfadiazine released into the environment.

Characterization and speciation of mercury in mosses and lichens from the high-altitude Tibetan Plateau.

The accumulation and species of mercury (Hg) in mosses and lichens collected from high-altitude Tibetan Plateau were studied. The altitudes of the sampling sites spanned from 1983 to 5147 m, and a total of 130 mosses and 52 lichens were analyzed. The total mercury (THg) contents in mosses and lichens were in the ranges of 13.1-273.0 and 20.2-345.9 ng/g, respectively. The average ratios of methylmercury (MeHg) in THg in mosses and lichens were 2.4 % (0.3-11.1 %) and 2.7 % (0.4-9.6 %), respectively, which were higher than those values reported in other regions. The contents of THg in both mosses and lichens were not correlated with the THg in soils (p > 0.05). The lipid contents displayed a significantly positive correlation with concentrations of MeHg in mosses (r = 0.461, p < 0.01, n = 90), but not in lichens. The correlations between Hg contents in mosses and the altitudes, latitudes and longitudes of sampling sites indicated the mountain trapping and spatial deposition of Hg in the Tibetan Plateau.

Corynebacterium faecale sp. nov., isolated from the faeces of Assamese macaque.

A Gram-stain-positive, facultatively anaerobic, short rod-shaped, oxidase-negative and non-motile novel strain, designated YIM 101505T, was isolated from the faeces of a primate, Assamese macaque, and was studied to determine its taxonomic position. The cell wall contained meso-diaminopimelic acid and short-chain mycolic acids. Whole cell sugars were mannose, galactose and arabinose as major components. The major fatty acids (>10 %) were C18 : 1ω9c, C16 : 0 and C17 : 1ω8c and the major menaquinone was MK-9(H2). The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, glycolipid and six unidentified lipids. The new isolate shared most of the typical chemotaxonomic characteristics of members of the genus Corynebacterium. The closest related species was Corynebacterium efficiens based on 16S rRNA gene (98.1 % similarity) and partial rpoB gene (91.4 % similarity) sequences. Similarities with other species of this genus were below 97 % based on the 16S rRNA gene. The DNA-DNA hybridization value between YIM 101505T and C. efficiens DSM 44549T was 47.7±3.6 %. Moreover, the physiological and biochemical characteristics of YIM 101505T and C. efficiens DSM 44549T were different. Thus, strain YIM 101505T is considered to represent a novel member of the genus Corynebacterium, for which the name Corynebacterium faecale sp. nov. is proposed. The type strain is YIM 101505T (=DSM 45971T=CCTCC AB 2013226T).

Methylated ZNF582 gene as a marker for triage of women with Pap smear reporting low-grade squamous intraepithelial lesions - a Taiwanese Gynecologic Oncology Group (TGOG) study.

OBJECTIVE: Our previous work revealed that host genes ZNF582, PTPRR, PAX1, and SOX1 are highly methylated in cervical intraepithelial neoplasias grade 3 or worse (CIN3(+)). In this study, we used a standardized testing assay to evaluate the clinical efficacy of these biomarkers in the triage of cytological diagnoses of low-grade squamous intraepithelial lesions (LSILs), and compared the performance with human papillomavirus (HPV) testing. METHODS: This 2-year multicenter prospective study examined a population of 230 women from 12 medical centers who were diagnosed with LSILs on cervical cytology. Cervical scrapings were obtained prior to a colposcopy-directed biopsy for quantitative methylation analysis of ZNF582, PTPRR, PAX1, and SOX1, and HPV testing. Using logistic regression and receiver operating characteristic curve analyses, the abilities of methylated genes and HPV to predict CIN3(+) were assessed. RESULTS: Fifteen (6.5%) of the 230 women with a cytological diagnosis of LSIL were confirmed to have CIN3(+) after a colposcopy-directed biopsy. Among the 4 methylated genes, ZNF582 was found to be the best biomarker for detecting CIN3(+). The sensitivities for methylated ZNF582 and HPV testing were 73% and 80%, and the specificities were 71% and 28%, respectively. The odds ratio for predicting CIN3(+) using methylated ZNF582 was 6.8 (95% confidence interval (CI) 2.1-22.1), which was much better than HPV testing (OR=1.6, 95% CI 0.4-5.8). CONCLUSION: This is the first study to show that ZNF582 methylation analysis of cervical swabs may be a promising choice in the positive triage of cytological diagnoses of LSILs.

Matrix-assisted laser desorption/ionization mass spectrometry imaging of cardiolipins in rat organ sections.

Cardiolipin (CL) is a class of phospholipid tightly associated with the mitochondria functions and a prime target of oxidative stress. Peroxidation of CL dissociates its bound cytochrome C, a phenomenon that reflects oxidative stress sustained by the organ and a trigger for the intrinsic apoptotic pathway. However, CL distribution in normal organ tissues has yet to be documented. Fresh rat organs were snap-frozen, cut into cryosections that were subsequently desalted with ammonium acetate solution, and vacuum-dried. CL distribution in situ was determined using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technique on sections sublimed with 2,5-dihydroxybenzoic acid. CL images in rat cardiac ventricular section showed a homogeneous distribution of a single m/z 1447.9 ion species that was confirmed as the (18:2)4 CL by tandem mass spectrometry. The presence of low abundant (18:2)3(18:1) CL with the bulk (18:2)4 CL in quadriceps femoris rendered the muscle CL exhibiting a slightly deviated isotopic pattern from that of cardiac muscle. In rat liver, MALDI-MSI unveiled three CL-containing mass ranges, each with a unique in situ distribution pattern. Co-registration of the CL ion images with its stained liver section image further revealed the association of CLs in each mass range with the functional zones in the liver parenchyma and suggests the participation of in situ CLs with localized hepatic functions such as oxidation, conjugation, and detoxification. The advances in CL imaging offer an approach with molecular accuracy to reveal potentially dysregulated metabolic machineries in acute and chronic diseased states.

MOF Template-Derived Carbon Shell-Embedded CoP Hierarchical Nanosheet as Bifunctional Catalyst for Overall Water Splitting.

The design of earth-abundant and highly efficient bifunctional electrocatalysts for hydrogen evolution and oxygen evolution reactions (HER/OER) is crucial for hydrogen production through overall water splitting. Herein, we report a novel nanostructure consisting of vertically oriented CoP hierarchical nanosheet arrays with in situ-assembled carbon skeletons on a Ti foil electrode. The novel Zeolitic Imidazolate Framework-67 (ZIF-67) template-derived hierarchical nanosheet architecture effectively improved electrical conductivity, facilitated electrolyte transport, and increased the exposure of the active sites. The obtained bifunctional hybrid exhibited a low overpotential of 72 mV at 10 mA cm-2 and a small Tafel slope of 65 mV dec-1 for HER, and an improved overpotential of 329 mV and a Tafel slope of 107 mV dec-1 for OER. Furthermore, the assembled C@CoP||C@CoP electrolyzer showed excellent overall water splitting performance (1.63 V) at a current density of 10 mA cm-2 and superior durability. This work provides a structure engineering strategy for metal-organic framework (MOF) template-derived hybrids with outstanding electrocatalytic performance.

MALDI-mass spectrometry imaging of desalted rat brain sections reveals ischemia-mediated changes of lipids.

Ischemia-mediated lipidomic changes in rat brains were explored by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) profiling and imaging after in situ desalting which drastically simplified the spectral presentation of tissue lipids. Removal of interference from the massively changed cations in response to tissue damage permitted the revelation of subtle yet important lipidomic changes. The identities of the detected lipids were confirmed by MALDI tandem mass spectrometry (MALDI-MS/MS). The MALDI-MS imaging (MALDI-MSI) result of lysophosphatidylcholine 16:0 (LPC 16:0) in the desalted brain section appeared essentially identical to that of sodiated LPC 16:0 in the adjacent undesalted section and verified the suitability of the desalting method for the MALDI-MSI studies of lipids in tissue. Other than the consistently decreased phosphatidylcholine (PC) 16:0/18:1, images of PCs containing all saturated, or combined saturated and monounsaturated fatty acyl (MUFA) residues revealed their parenchymal increase by ischemia. Images of PCs containing polyunsaturated fatty acyl (PUFA) residues in normal cortex showed laminated patterns similar to cortical lamina. Ischemia reduced the abundance of PC 16:0/20:4 and PC 16:0/22:6 and disrupted the laminated distribution of the former. However, ischemia increased the subcortical abundance of PUFA-PCs containing stearoyl residue and confined their cortical increase within limited areas. Image of parenchymal sphingomyelin 18:0 (SM 18:0) showed its consistent decrease by ischemia that paralleled the increase of ceramide 18:0-H(2)O in region of moderate to high SM abundance. The above results presented the lipidomic changes largely different from previous MALDI-MSI results and suggested a window of intervention that may benefit the management of cerebrovascular accident and other brain injuries.

A simple desalting method for direct MALDI mass spectrometry profiling of tissue lipids.

Direct MALDI-mass spectrometry (MALDI-MS) profiling of tissue lipids often observes isobaric phosphatidylcholine (PC) species caused by the endogenous alkali metal ions that bias the relative abundance of tissue lipids. Fresh rat brain cryosections were washed with 70% ethanol (EtOH), water (H2O), or 150 mM ammonium acetate (NH4Ac), and the desalting effectiveness of each fluid was evaluated by MALDI-MS profiling of PC and sphingomyelin (SM) species in tissue and in the washing runoff. The results indicated that EtOH and H2O only partially desalted the tissue lipids, yet both substantially displaced the tissue lipids to the washing runoffs. On the other hand, NH4Ac effectively desalted the tissue lipids and produced a runoff containing no detectable PCs or SMs. NH4Ac wash also unveiled the underlying changes of PCs and SMs in the infarcted rat cortex previously masked by edema-caused increase of tissue sodium. The MS/MS of an isobaric PC in the infarcted cortex revealed the precursor change as the result of NH4Ac wash and confirmed the desalting effectiveness of such wash. Other than desalting, NH4Ac wash also removes contaminants in tissue, enhances the overall spectral quality, and benefits additionally in profiling of biological molecules in tissue.

Complete resolution of diffuse placenta increta in a primigravida with twin pregnancy: sonographic monitoring.

We report a case of timely diagnosis of placenta increta by sonography during the third stage of labor, which avoided any attempt at manual removal of a retained placenta and thus prevented additional postpartum bleeding. The use of intra-cervical injection of vasopressin and methotrexate and application of transcatheter arterial embolization of bilateral uterine arteries and right internal iliac arteries resulted in a good outcome.

Direct profiling of phospholipids and lysophospholipids in rat brain sections after ischemic stroke.

Stroke, a deleterious cerebrovascular event, is caused by a critical reduction in the blood flow to the brain parenchyma that leads to brain injury and loss of brain functions. The inflammatory responses following ischemia often aggravate the neurological damage. Several pro-inflammatory mediators released after stroke are closely related to the metabolism of phospholipids. In this study we directly profiled the changes in phospholipids in the infarcted rat cerebral cortex 24 hours after middle cerebral artery occlusion (MCAO) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Several phosphatidylcholine (PC) species and sphingomyelin (SM) were significantly decreased after infarction. The cationization pattern of the remaining PCs showed a prominent shift from a mostly potassiated or protonated form to a predominantly sodiated pattern. Stroke also elevated the lysophosphatidylcholines (LPCs) and heme in tissue. The isobaric pairs in PC and LPC classes were resolved by masses through their respective alkali metal adducts in the presence of CsCl. The major fatty acyl LPC species were also structurally confirmed by MALDI-MS/MS. Overall, the results described the changes in PC and LPC species in the infarcted rat cortex. The elevated tissue levels of LPCs and heme signify the ongoing pathological lipid breakdown and the state of parenchymal inflammation. The elevated LPC level in tissue suggests a means of intervention through lysophospholipid metabolism that could potentially benefit the management of stroke and other acute neurological injuries.

An immunocompromised woman with severe molluscum contagiosum that responded well to topical imiquimod: a case report and literature review.

Molluscum contagiosum is a common condition that often occurs in children, sexually active young adults, and immunocompromised patients. Generally, molluscum contagiosum lesions are self-limited. They often resolve spontaneously. We report a severe case of genital molluscum contagiosum in a patient with Sjögren syndrome. Her vulvar lesions responded to topical 5% imiquimod cream.

Potential role of intravenous immunoglobulin in the management of peripartum maternal thrombocytopenia due to various causes.

Severe maternal thrombocytopenia resulting in hemorrhage is often associated with high mortality. Three cases of severe maternal thrombocytopenia in association with heparin-induced thrombocytopenia (HIT), HELLP syndrome, and systemic lupus erythematosus (SLE) were successfully managed using intravenous immunoglobulin (IVIG). IVIG can reduce the severity of thrombocytopenia and hemolysis, stabilize lupus activity, prevent peripartum hemorrhage, and shorten hospitalization, but it may induce reversible interstitial nephritis and membranous glomerulonephritis. IVIG may be beneficial in the management of severe peripartum maternal thrombocytopenia in association with HIT, HELLP syndrome, and SLE.

Phthalates in plastic bottled non-alcoholic beverages from China and estimated dietary exposure in adults.

Concentrations of six phthalates were determined in 69 plastic bottled non-alcoholic beverages collected from marketplaces in China. Di-n-butyl phthalate (DBP) and di-(2-ethylhexyl)-phthalate (DEHP) were the most detected compounds with frequencies of 100%. Dimethyl phthalate was found less, with a mean frequency of almost 34%. The samples were divided into seven groups. The frequencies of phthalates in these groups ranged from 6.67% to 100%, which indicated that different types of beverages were differently contaminated by phthalates. DEHP contained the highest mean and median concentrations (1.60 ng g-1 and 0.62 ng g-1), followed by DBP (1.34 ng g-1 and 0.27 ng g-1). For DBP, the highest phthalate concentration of 14.3 ng g-1 was measured. The results of estimated daily intake (EDI) showed that the risk of Chinese adults exposed to these 6 phthalates in beverages examined was lower than the reference doses as suggested by the United States Environmental Protection Agency. The range of EDI values was between 1.77 × 10-4 µg kg-bw-1 day-1 and 0.478 µg kg-bw-1 day-1.

Distinct toxicological characteristics and mechanisms of Hg2+ and MeHg in Tetrahymena under low concentration exposure.

Inorganic divalent mercury complexes (Hg2+) and monomethylmercury complexes (MeHg) are the main mercury species in aquatic systems and their toxicity to aquatic organisms is of great concern. Tetrahymena is a type of unicellular eukaryotic protozoa located at the bottom of food chain that plays a fundamental role in the biomagnification of mercury. In this work, the dynamic accumulation properties, toxicological characteristics and mechanisms of Hg2+ and MeHg in five Tetrahymena species were evaluated in detail. The results showed that both Hg2+ and MeHg were ingested and exhibited inhibitory effects on the proliferation or survival of Tetrahymena species. However, the ingestion rate of MeHg was significantly higher than that of Hg2+. The mechanisms responsible for the toxicity of MeHg and Hg2+ were different, although both chemicals altered mitochondrial membrane potential (MMP). MeHg disrupted the integrity of membranes while Hg2+ had detrimental effects on Tetrahymena as a result of the increased generation of reactive oxygen species (ROS). In addition, the five Tetrahymena species showed different capacities in accumulating Hg2+ and MeHg, with T. corlissi exhibiting the highest accumulations. The study also found significant growth-promoting effect on T. corlissi under low concentration exposure (0.003 and 0.01µg Hg/mL (15 and 50nM)), suggesting different effect and mechanism that should be more closely examined when assessing the bioaccumulation and toxicity of mercury in aquatic ecosystems.