Identification and characterization of a novel hydroxylamine oxidase, DnfA, that catalyzes the oxidation of hydroxylamine to N2.

Nitrogen (N2) gas in the atmosphere is partially replenished by microbial denitrification of ammonia. Recent study has shown that Alcaligenes ammonioxydans oxidizes ammonia to dinitrogen via a process featuring the intermediate hydroxylamine, termed "Dirammox" (direct ammonia oxidation). However, the unique biochemistry of this process remains unknown. Here, we report an enzyme involved in Dirammox that catalyzes the conversion of hydroxylamine to N2. We tested previously annotated proteins involved in redox reactions, DnfA, DnfB, and DnfC, to determine their ability to catalyze the oxidation of ammonia or hydroxylamine. Our results showed that none of these proteins bound to ammonia or catalyzed its oxidation; however, we did find DnfA bound to hydroxylamine. Further experiments demonstrated that, in the presence of NADH and FAD, DnfA catalyzed the conversion of 15N-labeled hydroxylamine to 15N2. This conversion did not happen under oxygen (O2)-free conditions. Thus, we concluded that DnfA encodes a hydroxylamine oxidase. We demonstrate that DnfA is not homologous to any known hydroxylamine oxidoreductases and contains a diiron center, which was shown to be involved in catalysis via electron paramagnetic resonance experiments. Furthermore, enzyme kinetics of DnfA were assayed, revealing a Km of 92.9 ± 3.0 µM for hydroxylamine and a kcat of 0.028 ± 0.001 s-1. Finally, we show that DnfA was localized in the cytoplasm and periplasm as well as in tubular membrane invaginations in HO-1 cells. To the best of our knowledge, we conclude that DnfA is the first enzyme discovered that catalyzes oxidation of hydroxylamine to N2.

Innovative approach to identify multigenomic and environmental interactions associated with birth defects in family-based hybrid designs.

Genes, including those with transgenerational effects, work in concert with behavioral, environmental, and social factors via complex biological networks to determine human health. Understanding complex relationships between causal factors underlying human health is an essential step towards deciphering biological mechanisms. We propose a new analytical framework to investigate the interactions between maternal and offspring genetic variants or their surrogate single nucleotide polymorphisms (SNPs) and environmental factors using family-based hybrid study design. The proposed approach can analyze diverse genetic and environmental factors and accommodate samples from a variety of family units, including case/control-parental triads, and case/control-parental dyads, while minimizing potential bias introduced by population admixture. Comprehensive simulations demonstrated that our innovative approach outperformed the log-linear approach, the best available method for case-control family data. The proposed approach had greater statistical power and was capable to unbiasedly estimate the maternal and child genetic effects and the effects of environmental factors, while controlling the Type I error rate against population stratification. Using our newly developed approach, we analyzed the associations between maternal and fetal SNPs and obstructive and conotruncal heart defects, with adjustment for demographic and lifestyle factors and dietary supplements. Fourteen and 11 fetal SNPs were associated with obstructive and conotruncal heart defects, respectively. Twenty-seven and 17 maternal SNPs were associated with obstructive and conotruncal heart defects, respectively. In addition, maternal body mass index was a significant risk factor for obstructive defects. The proposed approach is a powerful tool for interrogating the etiological mechanism underlying complex traits.

Novel Alcaligenes ammonioxydans sp. nov. from wastewater treatment sludge oxidizes ammonia to N2 with a previously unknown pathway.

Heterotrophic nitrifiers are able to oxidize and remove ammonia from nitrogen-rich wastewaters but the genetic elements of heterotrophic ammonia oxidation are poorly understood. Here, we isolated and identified a novel heterotrophic nitrifier, Alcaligenes ammonioxydans sp. nov. strain HO-1, oxidizing ammonia to hydroxylamine and ending in the production of N2 gas. Genome analysis revealed that strain HO-1 encoded a complete denitrification pathway but lacks any genes coding for homologous to known ammonia monooxygenases or hydroxylamine oxidoreductases. Our results demonstrated strain HO-1 denitrified nitrite (not nitrate) to N2 and N2 O at anaerobic and aerobic conditions respectively. Further experiments demonstrated that inhibition of aerobic denitrification did not stop ammonia oxidation and N2 production. A gene cluster (dnfT1RT2ABCD) was cloned from strain HO-1 and enabled E. coli accumulated hydroxylamine. Sub-cloning showed that genetic cluster dnfAB or dnfABC already enabled E. coli cells to produce hydroxylamine and further to 15 N2 from (15 NH4 )2 SO4 . Transcriptome analysis revealed these three genes dnfA, dnfB and dnfC were significantly upregulated in response to ammonia stimulation. Taken together, we concluded that strain HO-1 has a novel dnf genetic cluster for ammonia oxidation and this dnf genetic cluster encoded a previously unknown pathway of direct ammonia oxidation (Dirammox) to N2 .

The damage and tolerance mechanisms of Phaffia rhodozyma mutant strain MK19 grown at 28 °C.

BACKGROUND: Phaffia rhodozyma has many desirable properties for astaxanthin production, including rapid heterotrophic metabolism and high cell densities in fermenter culture. The low optimal temperature range (17-21 °C) for cell growth and astaxanthin synthesis in this species presents an obstacle to efficient industrial-scale astaxanthin production. The inhibition mechanism of cell growth at > 21 °C in P. rhodozyma have not been investigated. RESULTS: MK19, a mutant P. rhodozyma strain grows well at moderate temperatures, its cell growth was also inhibited at 28 °C, but such inhibition was mitigated, and low biomass 6 g/L was obtained after 100 h culture. Transcriptome analysis indicated that low biomass at 28 °C resulted from strong suppression of DNA and RNA synthesis in MK19. Growth inhibition at 28 °C was due to cell membrane damage with a characteristic of low mRNA content of fatty acid (f.a.) pathway transcripts (acc, fas1, fas2), and consequent low f.a. CONTENT: Thinning of cell wall and low mannose content (leading to loss of cell wall integrity) also contributed to reduced cell growth at 28 °C in MK19. Levels of astaxanthin and ergosterol, two end-products of isoprenoid biosynthesis (a shunt pathway of f.a. biosynthesis), reached 2000 µg/g and 7500 µg/g respectively; ~2-fold higher than levels at 21 or 25 °C. Abundance of ergosterol, an important cell membrane component, compensated for lack of f.a., making possible the biomass production of 6 g/L for MK19 at 28 °C. CONCLUSIONS: Inhibition of growth of P. rhodozyma at 28 °C results from blocking of DNA, RNA, f.a., and cell wall biosynthesis. In MK19, abundant ergosterol made possible biomass production 6 g/L at 28 °C. Significant accumulation of astaxanthin and ergosterol indicated an active MVA pathway in MK19 at 28 °C. Strengthening of the MVA pathway can be a feasible metabolic engineering approach for enhancement of astaxanthin synthesis in P. rhodozyma. The present findings provide useful mechanistic insights regarding adaptation of P. rhodozyma to 28 °C, and improved understanding of feasible metabolic engineering techniques for industrial scale astaxanthin production by this economically important yeast species.

Generalized multifactor dimensionality reduction approaches to identification of genetic interactions underlying ordinal traits.

The manifestation of complex traits is influenced by gene-gene and gene-environment interactions, and the identification of multifactor interactions is an important but challenging undertaking for genetic studies. Many complex phenotypes such as disease severity are measured on an ordinal scale with more than two categories. A proportional odds model can improve statistical power for these outcomes, when compared to a logit model either collapsing the categories into two mutually exclusive groups or limiting the analysis to pairs of categories. In this study, we propose a proportional odds model-based generalized multifactor dimensionality reduction (GMDR) method for detection of interactions underlying polytomous ordinal phenotypes. Computer simulations demonstrated that this new GMDR method has a higher power and more accurate predictive ability than the GMDR methods based on a logit model and a multinomial logit model. We applied this new method to the genetic analysis of low-density lipoprotein (LDL) cholesterol, a causal risk factor for coronary artery disease, in the Multi-Ethnic Study of Atherosclerosis, and identified a significant joint action of the CELSR2, SERPINA12, HPGD, and APOB genes. This finding provides new information to advance the limited knowledge about genetic regulation and gene interactions in metabolic pathways of LDL cholesterol. In conclusion, the proportional odds model-based GMDR is a useful tool that can boost statistical power and prediction accuracy in studying multifactor interactions underlying ordinal traits.

Pseudomonas nitrititolerans sp. nov., a nitrite-tolerant denitrifying bacterium isolated from a nitrification/denitrification bioreactor.

A nitrite-tolerant denitrifying bacterium, strain GL14T, was isolated from the nitrification/denitrification bioreactor in our laboratory. Strain GL14T was Gram-stain-negative, rod-shaped, non-spore-forming, facultatively anaerobic and motile by means of a single polar flagellum. Phylogenetic analyses based on 16S rRNA gene sequences indicated that it was assigned to the genus Pseudomonas with highest 16S rRNA gene sequence similarity (98.77 %) to Pseudomonas xanthomarina DSM 18231T and Pseudomonassongnenensis NEAU-ST5-5T, followed by Pseudomonasstutzeri ATCC 17588T (98.42 %), Pseudomonaskunmingensis HL22-2T (98.29 %) and Pseudomonaszhaodongensis NEAU-ST5-21T (98.22 %). Phylogenetic analysis based on both concatenated sequences of the 16S rRNA gene and two housekeeping genes (gyrB and rpoD) and genome sequences further clarified the intrageneric phylogenetic position of strain GL14T. The DNA G+C content of GL14T was 63.1 mol%. The results of digital DNA-DNA hybridization (highest 24.2 % of DNA-DNA relatedness) based on the Genome-to-Genome Distance Calculator and average nucleotide identity analyses (highest 80.23 %) confirmed that the strain was distinctly delineated from known species of the genus Pseudomonas. The major fatty acids were summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), C16 : 0, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), C17 : 0cyclo and C12 : 0. The respiratory quinone was ubiquinone Q-9. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Based on the phylogenetic, genomic, phenotypic and chemotaxonomic analyses, it was concluded that strain GL14T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas nitrititolerans sp. nov. is proposed. The type strain is GL14T (=CGMCC 1.13874T=NBRC 113853T).

GMDR: Versatile Software for Detecting Gene-Gene and Gene-Environ- ment Interactions Underlying Complex Traits.

Identification of multifactor gene-gene (G×G) and gene-environment (G×E) interactions underlying complex traits poses one of the great challenges to today's genetic study. Development of the generalized multifactor dimensionality reduction (GMDR) method provides a practicable solution to problems in detection of interactions. To exploit the opportunities brought by the availability of diverse data, it is in high demand to develop the corresponding GMDR software that can handle a breadth of phenotypes, such as continuous, count, dichotomous, polytomous nominal, ordinal, survival and multivariate, and various kinds of study designs, such as unrelated case-control, family-based and pooled unrelated and family samples, and also allows adjustment for covariates. We developed a versatile GMDR package to implement this serial of GMDR analyses for various scenarios (e.g., unified analysis of unrelated and family samples) and large-scale (e.g., genome-wide) data. This package includes other desirable features such as data management and preprocessing. Permutation testing strategies are also built in to evaluate the threshold or empirical p values. In addition, its performance is scalable to the computational resources. The software is available at http://www.soph.uab.edu/ssg/software or http://ibi.zju.edu.cn/software.

Thalassotalea marina sp. nov., isolated from a marine recirculating aquaculture system, reclassification of Thalassomonas eurytherma as Thalassotalea eurytherma comb. nov. and emended description of the genus Thalassotalea.

A Gram-stain-negative, facultatively anaerobic bacterium, strain QBLM2T, was isolated from rearing water of a marine recirculating aquaculture system in Tianjin, China. Its taxonomic position was investigated through a polyphasic approach. Cells of strain QBLM2T were non-spore-forming rods, motile by means of a single polar flagellum. Positive for oxidase and catalase. Growth occurred at 15-40 °C (optimum 30 °C), at pH 6.5-10.5 (optimum pH 7.5-8.5) and in the presence of 0-5.0 % (w/v) NaCl (optimum 3 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain QBLM2T formed a distinct lineage within the genus Thalassotalea and exhibited sequence similarities of 94.5-96.3 % to members of the genus Thalassotalea. The predominant fatty acids (>10 %) were C17 : 1ω8c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. Ubiquinone 8 (Q-8) was the major ubiquinone. The DNA G+C content was 37.1 mol%. Based on the data above, strain QBLM2T is considered to represent a novel species of the genus Thalassotalea, for which the name Thalassotalea marina sp. nov. is proposed. The type strain is QBLM2T ( = CGMCC 1.12814T = KCTC 42731T). Phylogenetic analyses indicated that Thalassomonas eurytherma Za6a-12T fell within the genus Thalassotalea, so it is reclassified as Thalassotalea eurytherma comb. nov. and the description of the genus Thalassotalea is emended.

Belliella aquatica sp. nov., isolated from a saline lake.

A Gram-staining-negative bacterium, strain TS-T86(T), was isolated from Lake Tuosu, a saline lake (salinity 5.4%, w/w) in Qaidam basin, China. Its taxonomic position was determined by using a polyphasic approach. Strain TS-T86(T) was strictly heterotrophic, aerobic and catalase- and oxidase-positive. Cells were non-spore-forming, non-motile rods, 0.4-0.6 µm wide and 1.2-2.3 µm long. Growth was observed in the presence of 0-9.0% (w/v) NaCl (optimum, 2.0%), at 4-35 °C (optimum, 25 °C) and at pH 7.0-10.5 (optimum, pH 8.5-9.0). Strain TS-T86(T) contained MK-7 as the predominant respiratory quinone. The major fatty acids (>10%) were iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 1ω9c, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipids consisted of phosphatidylethanolamine, an unknown phospholipid, six unidentified aminolipids and two uncharacterized lipids. The DNA G+C content was 35 mol% (T m). Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T86(T) was associated with the genus Belliella, and showed the highest sequence similarity to Belliella baltica BA134(T) (98.5 %) and then to Belliella kenyensis No.164(T) (95.7%) and Belliella pelovolcani CC-SAL-25(T) (95.3 %). DNA-DNA relatedness of strain TS-T86(T) to Belliella baltica DSM 15883(T) was 32 ± 3%. It is concluded that strain TS-T86(T) represents a novel species of the genus Belliella, for which the name Belliella aquatica sp. nov. is proposed. The type strain is TS-T86(T) ( = CGMCC 1.12479(T) = JCM 19468(T)).

Pseudomonas salina sp. nov., isolated from a salt lake.

A Gram-staining-negative, facultatively aerobic bacterium, strain XCD-X85(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/v) in Qaidam basin, Qinghai province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X85(T) were non-endospore-forming rods, 0.4-0.6 µm wide and 1.0-1.6 µm long, and motile by means of a single polar flagellum. Strain XCD-X85(T) was catalase- and oxidase-positive. Growth was observed in the presence of 0-12.0% (w/v) NaCl (optimum, 1.0-2.0%) and at 4-35 °C (optimum, 25-30 °C) and pH 6.5-10.5 (optimum, pH 8.0-8.5). Strain XCD-X85(T) contained (>10%) summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C12 : 0, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the predominant fatty acids. The major respiratory quinone was ubiquinone 9 (Q-9). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 57.4 mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X85(T) was associated with the genus Pseudomonas, and showed highest 16S rRNA gene sequence similarities to Pseudomonas pelagia CL-AP6(T) (99.0%) and Pseudomonas bauzanensis BZ93(T) (96.8%). DNA-DNA relatedness of strain XCD-X85T to P. pelagia JCM 15562(T) was 19 ± 1%. On the basis of the data presented above, it is concluded that strain XCD-X85(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salina sp. nov. is proposed. The type strain is XCD-X85(T) ( = CGMCC 1.12482(T) = JCM 19469(T)).

Marivita lacus sp. nov., isolated from a saline lake.

A Gram-staining-negative, strictly heterotrophic and aerobic bacterium, strain TS-T44T, was isolated from a saline lake, Tuosu Lake in Qaidam basin, Qinghai province, China. Its taxonomic position was investigated using a polyphasic approach. Cells of strain TS-T44T were non-endospore-forming, non-motile rods, 0.8-1.2 µm wide and 1.2-3.0 µm long. Catalase- and oxidase-positive. Growth occurred in the presence of up to 8 % (w/v) NaCl (optimum, 3.0 %) and at 15-35 °C (optimum, 25 °C) and pH 7.0-10.0 (optimum, pH 7.5-8.5). C18 : 1ω7c was the predominant fatty acid. The major respiratory quinone was Q-10. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid and an unknown lipid. The DNA G+C content was 65.5 mol% [determined from the melting temperature (Tm)]. Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T44T was associated with the genus Marivita and showed highest sequence similarity to Marivita cryptomonadis CL-SK44T (97.7 %), Marivita litorea CL-JM1T (97.5 %) and Marivita geojedonensis DPG-138T (97.3 %), and < 97 % to other species. DNA-DNA relatedness of strain TS-T44T to M. cryptomonadis JCM 15447T, M. litorea JCM 15446T and M. geojedonensis KCTC 23882T was 23 ± 3 %, 33 ± 4 % and 35 ± 2 %, respectively. Based on the data presented, it is concluded that strain TS-T44T represents a novel species of the genus Marivita, for which the name Marivita lacus sp. nov. is proposed. The type strain is TS-T44T ( = CGMCC 1.12478T = JCM 19516T).

Frequency and distribution pattern of minor salivary gland tumors in a northeastern Chinese population: a retrospective study of 485 patients.

PURPOSE: The relative frequency of individual minor salivary gland tumors (MSGTs) is not well documented in the literature. The aim of this study was to determine the range and demographics of all histologically diagnosed MSGTs in a northeastern Chinese population. MATERIALS AND METHODS: A total of 485 cases of MSGT were retrospectively studied. The files of the Department of Oral and Maxillofacial Pathology, School of Stomatology, China Medical University served as a source of material for this study. All epithelial tumors from minor salivary glands accessioned from August 2004 to April 2014 were analyzed for demographic features, anatomic location of tumors, and pathologic classification. Tumors were classified according to the 2005 World Health Organization classification of salivary gland tumors. Statistical analysis was performed using analysis of variance. RESULTS: MSGTs were identified in 485 (2.60%) of 18,670 accessed cases. There were 268 (55.26%) benign and 217 (44.74%) malignant tumors. Female outnumbered male patients (male-to-female ratio, 1:1.43). The mean ages of patients with benign and malignant MSGTs were 47.58 and 51.51 years, respectively. Pleomorphic adenoma and adenoid cystic carcinoma were the most frequent types of benign and malignant tumors, respectively. The palate was the most commonly affected site (64.74%), followed by the buccal mucosa (7.63%) and the tongue (5.98%). CONCLUSIONS: From the results of this study and a review of the literature, it is suggested that MSGTs in the northeastern Chinese population may be characterized by a higher incidence of MSGTs than in the populations of other reviewed regions, a higher incidence of myoepithelioma, a rarer occurrence of polymorphous low-grade adenocarcinoma, and an absence of canalicular adenoma occurrence.

Transcranial alternating current stimulation improves quality of life in Parkinson's disease: study protocol for a randomized, double-blind, controlled trial.

BACKGROUND: The neural cells in the brains of patients with Parkinson's disease (PWP) display aberrant synchronized oscillatory activity within the beta frequency range. Additionally, enhanced gamma oscillations may serve as a compensatory mechanism for motor inhibition mediated by beta activity and also reinstate plasticity in the primary motor cortex affected by Parkinson's disease. Transcranial alternating current stimulation (tACS) can synchronize endogenous oscillations with exogenous rhythms, thereby modulating cortical activity. The objective of this study is to investigate whether the addition of tACS to multidisciplinary intensive rehabilitation treatment (MIRT) can improve symptoms of PWP so as to enhance the quality of life in individuals with Parkinson's disease based on the central-peripheral-central theory. METHODS: The present study was a randomized, double-blind trial that enrolled 60 individuals with Parkinson's disease aged between 45 and 70 years, who had Hoehn-Yahr scale scores ranging from 1 to 3. Participants were randomly assigned in a 1:1 ratio to either the tACS + MIRT group or the sham-tACS + MIRT group. The trial consisted of a two-week double-blind treatment period followed by a 24-week follow-up period, resulting in a total duration of twenty-six weeks. The primary outcome measured the change in PDQ-39 scores from baseline (T0) to 4 weeks (T2), 12 weeks (T3), and 24 weeks (T4) after completion of the intervention. The secondary outcome assessed changes in MDS-UPDRS III scores at T0, the end of intervention (T1), T2, T3, and T4. Additional clinical assessments and mechanistic studies were conducted as tertiary outcomes. DISCUSSION: The objective of this study is to demonstrate that tACS can enhance overall functionality and improve quality of life in PWP, based on the framework of MIRT. Additionally, it seeks to establish a potential correlation between these therapeutic effects and neuroplasticity alterations in relevant brain regions. The efficacy of tACS will be assessed during the follow-up period in order to optimize neuroplasticity and enhance its potential impact on rehabilitation efficiency for PWP. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300071969. Registered on 30 May 2023.

Progress of Dicyanomethylene-4H-Pyran Derivatives in Biological Sensing Based on ICT Effect.

As one of the typical fluorescent cores, dicyanomethylene-4H-pyran (DCM) derivatives exhibit excellent photophysical and photochemical properties, such as large Stokes shift, excellent light stability, and tunable near-infrared (NIR) emission. The luminescence mechanism of DCM probes mainly depends on the intramolecular charge transfer (ICT). Hence, by regulating the ICT process, the probes can specifically act on the target molecule. Accordingly, a series of NIR DCM probes have been constructed to detect the ions, reactive oxygen species (ROS), and biological macromolecules in cells. However, there is no relevant review to summarize it at present. This minireview mainly summarizes the NIR DCM probes based on ICT effect and their applications in biosensors and biological imaging in recent years. This will be beneficial to innovatively construct new DCM probes and actively promote their application in the future.

Fluorescence Enhancement of Dicyanomethylene-4H-Pyran Derivatives in Solid State for Visualization of Latent Fingerprints.

The efficient development of latent fingerprint (LFP) is attractively important for criminal investigation. The low-cost and high-contrast developer is still a challenge. In this study, we designed and synthesized dicyanomethylene-4H-pyran (DCM) derivatives PZ-DCM and Boc-PZ-DCM by introducing of large steric hindrance group Boc, the solid-state fluorescence of DCM derivatives was greatly enhanced. The low-cost fluorescent LFP developers were prepared by blending with different proportion of montmorillonite (MMT). As a result, clear and high contrast fingerprint patterns were obtained with dusting method by the developer with 3% content of Boc-PZ-DCM. Furthermore, we employed the developer with 3% content of Boc-PZ-DCM to develop the sweat latent fingerprints on different substrates by powder dusting, and collected clear fingerprint patterns, indicating that the developer is universal. In a word, the Boc-PZ-DCM/MMT powder is a promising candidate for LFP developer.

Dirammox Is Widely Distributed and Dependently Evolved in Alcaligenes and Is Important to Nitrogen Cycle.

Nitrogen cycle is an essential process for environmental health. Dirammox (direct ammonia oxidation), encoded by the dnfT1RT2ABCD cluster, was a novel pathway for microbial N2 production defined in Alcaligenes ammonioxydans HO-1. Here, a copy of the cluster dnfT1RT2ABCD as a whole was proved to have existed and very conserved in all Alcaligenes genomes. Phylogenetic analyses based on 16S rRNA gene sequences and amino acid sequences of DnfAs, together with G + C content data, revealed that dnf cluster was evolved associated with the members of the genus Alcaligenes. Under 20% O2 conditions, 14 of 16 Alcaligenes strains showed Dirammox activity, which seemed likely taxon-related. However, the in vitro activities of DnfAs catalyzing the direct oxidation of hydroxylamine to N2 were not taxon-related but depended on the contents of Fe and Mn ions. The results indicated that DnfA is necessary but not sufficient for Dirammox activity. The fact that members of the genus Alcaligenes are widely distributed in various environments, including soil, water bodies (both freshwater and seawater), sediments, activated sludge, and animal-plant-associated environments, strongly suggests that Dirammox is important to the nitrogen cycle. In addition, Alcaligenes species are also commonly found in wastewater treatment plants, suggesting that they might be valuable resources for wastewater treatment.

Giant schwannoma of thoracic vertebra: A case report.

BACKGROUND: It is relatively rare for schwannomas to invade bone, but it is very rare for a large mass to form concurrently in the paravertebral region. Surgical resection is the only effective treatment. Because of the extensive tumor involvement and the many important surrounding structures, the tumor needs to be fully exposed. Most of the tumors are completely removed by posterior combined open-heart surgery to relieve spinal cord compression, restore the stability of the spine and maximize the recovery of nerve and spinal cord function. The main objective of this article is to present a schwannoma that had invaded the T5 and T6 vertebral bodies and formed a large paravertebral mass with simultaneous invasion of the spinal canal and compression of the spinal cord. CASE SUMMARY: A 40-year-old female suffered from intermittent chest and back pain for 8 years. Computed tomography and magnetic resonance imaging scans showed a paravertebral tumor of approximately 86 mm × 109 mm × 116 mm, where the adjacent T5 and T6 vertebral bodies were invaded by the tumor, the right intervertebral foramen was enlarged, and the tumor had invaded the spinal canal to compress the thoracic medulla. The preoperative puncture biopsy diagnosed a benign schwannoma. Complete resection of the tumor was achieved by a two-step operation. In the first step, the thoracic surgeon adopted a lateral approach to separate the thoracic tumor from the lung. In the second step, a spine surgeon performed a posterior midline approach to dissect the tumor from the vertebral junction through removal of the tumor from the posterior side and further resection of the entire T5 and T6 vertebral bodies. The large bone defect was reconstructed with titanium mesh, and the posterior root arch was nail-fixed. Due to the large amount of intraoperative bleeding, we performed tumor angioembolization before surgery to reduce and avoid large intraoperative bleeding. The postoperative diagnosis of benign schwannoma was confirmed by histochemical examination. There was no sign of tumor recurrence or spinal instability during the 2-year follow-up. CONCLUSION: Giant schwannoma is uncommon. In this case, a complete surgical resection of a giant thoracic nerve sheath tumor that invaded part of the vertebral body and compressed the spinal cord was safe and effective.

Apolipoprotein E Facilitates Amyloid-ß Oligomer-Induced Tau Phosphorylation.

Hyperphosphorylated tau is one of the key characteristics of Alzheimer's disease (AD), and tau pathology correlates with cognitive impairment in AD better than amyloid-ß (Aß) pathology. Thus, a complete understanding of the relevant factors involved in tau phosphorylation is important for AD treatment. APOEɛ4, the strongest genetic risk factor for AD, was found to be involved in tau pathology in frontotemporal dementia. This result indicated that apolipoprotein E (ApoE) may also participate in tau phosphorylation in AD. In the present study, we injected Aß oligomer (AßO) into the lateral ventricles of wild-type (WT) mice and apoE-/- mice to test the process of tau phosphorylation in the acute phase. We found that the phosphorylated tau and phosphokinase levels were higher in WT mice than in apoE-/- mice. These phenomena were also confirmed in vitro. ApoE ɛ4-treated apoE-/- neurons exhibited more phosphorylated tau than ApoE ɛ2- and ApoE ɛ3-treated neurons. We also found that AßO induced more serious inflammation in WT mice and in ApoE-positive cultured neurons. Anti-inflammatory treatment reduced the phosphorylated tau level induced by AßOs in ApoE-positive neurons. These results suggest that ApoE may facilitate the phosphorylation of tau induced by AßO via inflammation.

Optimization of extraction and purification of active fractions from Schisandra chinensis (Turcz.) and its osteoblastic proliferation stimulating activity.

Extraction and purification conditions of lignans from the fruits and seeds of Schisandra chinensis (Turcz.) were investigated through an orthogonal design of L(9)(3(4)) assay and macroporous resin technology. The extraction was optimized using 95% ethanol. For purification, the extract was dissolved in 30% ethanol, then adsorbed on a AB-8 macroporous resin and eluted with 30% ethanol and 70% ethanol successively, the latter resulting in a residue containing 65.2% of lignans. By HPLC analysis schisandrin, deoxyschisandrin and gamma-schisandrin were quantitatively determined. UMR 106 cells were used to examine the stimulatory activity of the lignans on osteoblasts in vitro. The lignans stimulated the proliferation of and the activity of alkaline phosphatase in the osteoblasts indicating their potential activity against osteoporosis.

[Butyl-p-hydroxybenzoate stimulates cystic fibrosis transmembrane conductance regulator Cl- transport].

This study is to investigate the activation effect of butyl-p-hydroxybenzoate (Bpb) on cAMP-dependent cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel gating. A stably transfected Fischer rat thyroid (FRT) epithelial cell lines co-expressing human CFTR and a green fluorescent protein mutant with ultra-high halide sensitivity (EYFP) were used to measure CFTR-mediated iodide influx rates. Bpb was identified as an effective activator of wild-type CFTR chloride channel, it can correct delta F508-CFTR gating defects but not processing defect. Bpb can't potentiate G551D-CFTR channel gating. The activity was reversible and dose-dependent. The study also provided clues that Bpb activates CFTR chloride channel through a direct binding mechanism. Our study identified Bpb as a novel structure CFTR activator. Bpb may be useful for probing CFTR channel gating mechanisms and as a lead compound to develop pharmacological therapy for CFTR-related disease.