Unraveling the mechanism of norfloxacin removal and fate of antibiotics resistance genes (ARGs) in the sulfur-mediated autotrophic denitrification via metagenomic and metatranscriptomic analyses.

The co-contamination of antibiotics and nitrogen has attracted widespread concerns due to its potential harm to ecological safety and human health. Sulfur-driven autotrophic denitrification (SAD) with low sludge production rate was adopted to treat antibiotics laden-organic deficient wastewater. Herein, a lab-scale sequencing batch reactor (SBR) was established to explore the simultaneous removal of nitrate and antibiotics, i.e. Norfloxacin (NOR), as well as microbial response mechanism of SAD sludge system towards NOR exposure. About 80.78 % of NOR was removed by SAD sludge when the influent NOR level was 0.5 mg/L, in which biodegradation was dominant removal route. The nitrate removal efficiency decreased slightly from 98.37 ± 0.58 % to 96.58 ± 1.03 % in the presence of NOR. Thiobacillus and Sulfurimonas were the most abundant sulfur-oxidizing bacteria (SOB) in SAD system, but Thiobacillus was more sensitive to NOR. The up-regulated genes related to Xenobiotics biodegradation and metabolism and CYP450 indicated the occurrence of NOR biotransformation in SAD system. The resistance of SAD sludge to the exposure of NOR was mainly ascribed to antibiotic efflux. And the effect of antibiotic inactivation was enhanced after long-term fed with NOR. The NOR exposure resulted in the increased level of antibiotics resistance genes (ARGs) and mobile genetic elements (MGEs). Besides, the enhanced ARG-MGE co-existence patterns further reveals the higher horizontal mobility potential of ARGs under NOR exposure pressures. The most enriched sulfur oxidizing bacterium Thiobacillus was a potential host for most of ARGs. This study provides a new insight for the treatment of NOR-laden wastewater with low C/N ratio based on the sulfur-mediated biological process.

Case Report: A novel TP53 mutation in a patient with quadruple wild-type gastrointestinal stromal tumor.

In this report, we present a case study of a 64-year-old female who was diagnosed with gastrointestinal stromal tumors (GISTs) and subsequently developed liver metastases despite undergoing radical resection. Next-generation sequencing (NGS) assays indicated that the tumor lacked KIT/PDGFRA/SDH/RAS-P (RAS pathways, RAS-P) mutations, thereby classifying this patient as quadruple WT GIST (qGIST). Treatment with imatinib was initiated, and after 2.5 months, recurrence of the tumor and multiple metastases around the surgical site were observed. Consequently, the patient was switched to sunitinib treatment and responded well. Although she responded well to sunitinib, the patient died of tumor dissemination within 4 months. This case study highlights the potential efficacy of imatinib and the VEGFR-TKI sunitinib in treating qGIST patients harboring a TP53 missense mutation.

Injectable, pH-responsive hybrid hydrogels for the treatment of periodontitis.

Anti-inflammatory hydrogels have demonstrated great potential in the treatment of periodontitis. However, intelligent removal of reactive oxygen species (ROS) remains significantly challenging. In this study, a novel pH-responsive anti-inflammatory hydrogel was designed to treat periodontitis. We synthesized methacrylated alginate modified with a unique pH-sensitive phenylboronic acid through a one-step synthesis and then incorporated polydopamine particles loaded with minocycline to obtain a novel hydrogel under ultraviolet irradiation. Infrared and ultraviolet tests confirmed the successful preparation of the hydrogel. In environments with low pH, drug release rates significantly increased. In addition, in vitro cell experiments demonstrated excellent biocompatibility of the hydrogels. Furthermore, ROS detection revealed that the hydrogel effectively reduced cellular ROS levels and displayed excellent anti-inflammatory properties. These results strongly suggest that this novel pH-responsive anti-inflammatory hydrogel platform has tremendous potential for the treatment of periodontitis.

Effects of Hypoxic Environment on Periodontal Tissue through the ROS/TXNIP/NLRP3 Inflammasome Pathway.

There is low evidence for the possible association between obstructive sleep apnea-hypopnea syndrome (OSAHS) and periodontitis, necessitating further research. This study was aimed at investigating this association. For the in vitro study, 8-day-old Wistar rats were divided into the unilateral nasal obstruction group (UNO) and the sham surgery group (SHAM). Rats in the former group were subjected to UNO by cauterization of the external nostril at the age of 8 days. Immunofluorescence analysis, quantitative real-time polymerase chain reaction, and western blot were performed to assess the expression of thioredoxin-interacting protein (TXNIP), NLR family pyrin domain-containing 3 (NLRP3) inflammasome-associated factors, and interleukin-1ß (IL-1ß). Throughout the experimental period, the weights of rats in the two groups were similar. The mRNA and protein expression of TXNIP and IL-1ß was significantly higher in the UNO than in the SHAM groups. Compared with SHAM, NLRP3 inflammasome-associated factors were activated in the UNO group. For the in vitro study, a cellular hypoxia model was established by treating human periodontal ligament cells (HPDLCs) with cobalt chloride. The studies showed that hypoxia can induce an excessive production and accumulation of reactive oxygen species (ROS) in HPDLCs and induce abnormal expression of TNXIP, NLRP3 inflammasome-related factors, and IL-1ß. More importantly, N-acetylcysteine induced reduction of ROS in HPDLCs, downregulated TXNIP expression, inhibited the expression and aggregation of NLRP3 inflammasome-related factors, and abrogated the inflammatory response to hypoxia. In conclusion, hypoxia-induced ROS can activate the TXNIP/NLRP3 inflammasome signaling pathway in response to oxidative stress, resulting in the increased expression of inflammatory factors in HPDLCs. Our findings provide evidence for the mechanism underlying the possible association between OSAHS and periodontal disease.

The Alteration of Salivary Immunoglobulin A in Autism Spectrum Disorders.

Objectives: Autism spectrum disorders (ASD) are neurodevelopmental disorders with changes in the gut and oral microbiota. Based on the intimate relationship between the oral microbiota and oral mucosal immunity, this study aimed to investigate changes in salivary immunoglobulin A (IgA) level in ASD and the underlying mechanism for any such changes. Methods: We recruited 36 children diagnosed with ASD and 35 normally developing children and measured their salivary IgA content using enzyme-linked immunosorbent assay (ELISA). The valproate (VPA) -treated ASD mouse model was established by prenatal exposure to valproate and mouse salivary IgA content was also quantified by ELISA. The submandibular glands of VPA and control mice were isolated and analyzed using qRT-PCR, immunofluorescence staining, and flow cytometry. ASD-related Streptococci were co-incubated with the human salivary gland (HSG) cell line, and western blotting was used to detect the levels of relevant proteins. Results: We found that salivary IgA content was significantly decreased in patients with ASD and had a significant ASD diagnostic value. The salivary IgA content also decreased in VPA mice and was significantly correlated with autistic-like behaviors among them. The mRNA and protein levels of the polymeric immunoglobulin receptor (Pigr) were downregulated in the submandibular glands of VPA mice and the Pigr mRNA level was positively correlated with mouse salivary IgA content. HSG cells treated with ASD-related Streptococci had reduced PIGR protein level. Conclusion: Therefore, protective IgA levels were reduced in the saliva of individuals with ASD, which correlated with the bacteria-induced downregulation of Pigr in salivary glands. This study suggests a new direction for ASD diagnosis and prevention of oral diseases in ASD cohorts and provides evidence for the ASD mucosal immunophenotype in the oral cavity.

Adsorptive Removal of Low-Concentration Cr(VI) in Aqueous Solution by Mg-Al Layered Double Oxides.

To explore the adsorption removal mechanism of Mg-Al layered double oxides (LDOs) for low-concentration (≤ 5 mg L-1) Cr(VI), the adsorption kinetics, adsorption isotherms and its influencing factors were studied by batch experiments. Cr(VI) adsorption reached equilibrium after 6, 11 and 15 h for initial Cr(VI) concentrations of 1, 3 and 5 mg L-1, respectively, and the final adsorption efficiency exceeded 99.0%. The residual concentration of Cr(VI) was within the allowable limit of Drinking Water Quality Standard of World Health Organization (0.05 mg L-1). The experimental data fitted the pseudo-second-order and Freundlich models well. Mg-Al LDOs showed effective adsorption efficiency in the range of pH 3-9, and the adsorption efficiency was influenced by anions competition (HPO42- > SO42- > CO32- > NO3- > Cl-). The analyses of XRD, SEM and FT-IR spectra suggested adsorption Cr(VI) on Mg-Al LDOs was caused by capturing dichromate ions to reconstruct its structure. Therefore, Mg-Al LDOs is promising adsorbents for the low-concentration Cr(VI) treatment in polluted surface water and groundwater.

Iodine enrichment and the underlying mechanism in deep groundwater in the Cangzhou Region, North China.

The lack of information on the origin and behavior of iodine in deep groundwater restricts the development and use of groundwater resources. To address this issue, the Cangzhou region in the eastern North China Plain (NCP) was selected for a case study. In total, 296 deep groundwater samples were collected, their iodine concentrations were determined, and the distribution characteristics of iodine concentrations were analyzed. Iodine concentrations ranged from < 0.002 to 1.22 mg/L, with a mean of 0.19 mg/L; 42% of the samples had high iodine concentrations. The levels were higher in the east than in the west, and most of the samples with high iodine concentrations were obtained from sites east of the boundary between the Cangxian uplift and the Huanghua depression. The weathering and dissolution of iodine-bearing minerals and the leaching of marine sediments can facilitate iodine enrichment. In the Cangxian uplift, iodine was mainly a result of the conversion of organic iodine, while in the Huanghua depression, iodine enrichment was a factor of the conversion of IO3-. Overall, the main factors for the enrichment of iodine are the sedimentary environmental and the hydrodynamic conditions. Our results provide a theoretical basis to understand the occurrence of high iodine concentrations in deep groundwater.

Circadian transcription factor Dbp promotes rat calvarial osteoprogenitors osteogenic differentiation through Kiss1/GnRH/E2 signaling pathway loop.

To determine the mechanism by which D-site-binding protein (Dbp) regulates rat calvarial osteoprogenitors (OPCs) osteogenic differentiation. α-Smooth muscle actin (α-SMA) + rat calvarial OPCs were extracted and purified using immunomagnetic beads. Cells were transduced with Dbp-lentivirus and divided into Dbp knockdown, Dbp overexpression and vehicle groups. After osteogenic induction for 21 days, Alizarin red staining and alkaline phosphatase (ALP) activity were examined. Expression levels of Runx2, Ocn, Osterix, Bmp4, Kiss1, and GnRH were determined using a quantitative real-time polymerase chain reaction. The observed changes in Kisspeptin, GnRH, ERα, and Runx2 were further validated via Western blot analysis. Furthermore, E2 and GnRH secretion levels were detected via an enzyme-linked immunosorbent assay (ELISA). Chromatin immunoprecipitation (ChIP) and luciferase assay were used to assess the effects of Dbp on the Kiss1 gene promoter. The coexpression of Dbp and Kisspeptin or GnRH was also evaluated via immunofluorescence. Following osteogenic induction, Dbp overexpression significantly increased calcium nodule formation and ALP activity, as well as Runx2, Ocn, Osterix, Bmp4, Kiss1, and GnRH messenger RNA expression, while Dbp knockdown presented the opposite results. Western blot analysis and ELISA results showed that Dbp significantly promotes Runx2, E2/ERα, Kisspeptin, and GnRH expression. These findings were confirmed by the ChIP assay, which indicated that the estrogen receptor promotes Kisspeptin expression after binding to the Kiss1 gene promoter, which is regulated by Dbp. Immunofluorescence assay showed that Dbp coexpression with Kisspeptin or GnRH varied depending on Dbp expression levels. Collectively, the circadian transcription factor Dbp promotes α-SMA + rat calvarial OPCs osteoblastic differentiation through Kiss1/GnRH/E2 signaling pathway loop.

NH4+-N/NO3--N ratio controlling nitrogen transformation accompanied with NO2--N accumulation in the oxic-anoxic transition zone.

Although nitrogen (N) transformations have been widely studied under oxic or anoxic condition, few studies have been carried out to analyze the transformation accompanied with NO2--N accumulation. Particularly, the control of mixed N species in N-transformation remains unclear in an oxic-anoxic transition zone (OATZ), a unique and ubiquitous redox environment. To bridge the gap, in this study, OATZ microcosms were simulated by surface water and sediments of a shallow lake. The N-transformation processes and rates at different NH4+-N/NO3--N ratios, and NO2--N accumulations in these processes were evaluated. N-transformation process exhibited a turning point. Simultaneous nitrification and denitrification occurred in its early stage (first 10 days, dissolved oxygen (DO) ≥ 2 mg/L) and then denitrification dominated (after 10 days, DO < 2 mg/L), which were not greatly affected by the NH4+-N/NO3--N ratio, on the contrary, the transformation rates of NH4+-N and NO3--N were distinctly affected. The NH4+-N transformation rates were positively correlated with the NH4+-N/NO3--N ratio. The highest NO3--N transformation rate was observed at an NH4+-N/NO3--N ratio of 1:1 with organic carbon/NO3--N of 3.09. The NO2--N accumulation, which increased with the decrease in NH4+-N/NO3--N ratio, was also controlled by organic carbon concentration and type. The peak concentration of NO2--N accumulation occurred only when the NO3--N transformation rate was particularly low. Thus, NO2--N accumulation may be reduced by adjusting the control parameters related to N and organic carbon sources, which enhances the theoretical insights for N-polluted aquatic ecosystem bioremediation.

Characteristics and metabolic pathway of the bacteria for heterotrophic nitrification and aerobic denitrification in aquatic ecosystems.

The present study investigated the nitrogen removal characteristics and metabolic pathway of bacteria in aquatic ecosystem, with a focus on heterotrophic nitrification and aerobic denitrification. The bacteria demonstrated significant heterotrophic nitrification and aerobic denitrification capacity. The highest ammonium-N, nitrate-N, and nitrite-N removal efficiencies were 95.31 ± 0.11%, 98.91 ± 0.05%, and 98.79 ± 0.09%, respectively. The Monod model was used to estimate the maximum rate of substrate utilization (Rmo) and the half-saturation concentration (Ks) for the two substrates, i.e., ammonium and nitrate. The kinetic coefficients were 3.34 mg/L/d (Rmo) and 30.59 mg/L (Ks) for ammonium-N, respectively, and 14.23 mg/L/d (Rmo) and 215.24 mg/L (Ks) for nitrate-N, respectively. The effects of initial nitrogen (ammonium-N or nitrate-N) concentration, temperature, and dissolved oxygen (DO) on nitrogen removal rate were investigated using response surface methodology (RSM), and the optimal conditions for nitrogen removal were determined. The principal nitrogen removal pathway of the bacteria was proposed as complete heterotrophic nitrification and aerobic denitrification, which was performed by six key genera: Arthrobacter, Pseudomonas, Rhodococcus, Bacillus, Massilia, and Rhizobium. Chryseobacterium and other denitrifying species may also reduce nitrification products (NOX-) via aerobic denitrification.

The correlation analyses of bacterial community composition and spatial factors between freshwater and sediment in Poyang Lake wetland by using artificial neural network (ANN) modeling.

As one of the most important components of the lake ecosystem, microorganisms from the freshwater and sediment play an important role in many ecological processes. However, the difference and correlation of bacterial community between these two niches were not clear. This study investigated the diversity of microbial community of freshwater and sediment samples from fifteen locations in Poyang Lake wetland. The correlation between the bacterial community and physicochemical property of Poyang Lake wetland was analyzed by artificial neural network (ANN). Our results demonstrated that the freshwater and sediment bacterial community were dominated by groups of the Bacteroidetes (23.33%) and ß-Proteobacteria (22.54%) separately, whereas, Canalipalpata, Bacillariophyta, Gemmatimonadetes, and Verrucomicrobia were detected in freshwater niches only. Phylogenetic analysis further indicated that bacterial composition in freshwater significantly differed with the sediment niches. There are 34 unique species accounted for 85% in fresh water samples and 28 unique species accounted for 82% in sediment samples. Cluster analysis further proved that all the samples from freshwater niches clustered closely together, far from the rest sediment samples. ANN analysis revealed that the freshwater with high N and P nutrients will greatly increase the diversity of the bacterial communities. In general, both environmental physicochemical properties, not each factor independently, contributed to the shift in the bacterial community structure. The five tributaries (Gan, Fu, Xin, Rao, Xiu Rivers) play a vital role in shaping the bacterial communities of Poyang Lake. This study provides new insights for understanding of microbial community compositions and structures of Poyang Lake wetland.

Preparative Purification of Bioactive Compounds from Flos Chrysanthemi Indici and Evaluation of Its Antiosteoporosis Effect.

To understand the material basis and underlying molecular machinery of antiosteoporosis activity of the Flos Chrysanthemi Indici (FCI), the consequences of ethanol extract on the bone loss in mice induced due to ovariectomy (OVX) was evaluated. Also, the antiosteoporosis fraction obtained from the FCI ethanol extract was isolated and purified using a preparative high-speed countercurrent chromatography (HSCCC). The in vitro impact of the compounds was investigated on osteoblast proliferation and differentiation. The results revealed that ethyl acetate fraction with robust in vivo antiosteoporosis activity was obtained. The important compounds purified by HSCCC using gradient elution system included acacetin, apigenin, luteolin, and linarin. The four compounds enhanced the differentiation and proliferation of osteoblasts in MC3T3-E1 cells. They also augmented the mRNA levels of runt-related transcription factor 2 (Runx2), osteocalcin (OCN), osteopontin (OPN), and type I collagen (COL I). The AKT signaling pathway was also activated in MC3T3-E1 cells by the four compounds. The present study demonstrated that the antiosteoporosis effects of FCI did not depend on a single component, and HSCCC efficiently isolated and purified the antiosteoporosis bioactive compounds from FCI.

[Condylar morphological changes before and after orthodontic treatment for angle Class I malocclusion adult patients].

PURPOSE: To evaluate the diagnostic sensitivity and specificity of panoramic radiography in detection of maxillary teeth roots projecting into the maxillary sinus. METHODS: Paired panoramic radiographs and cone-beam CT (CBCT) images of maxilla from 110 subjects were analyzed. 42 males and 68 females (15~36 years old) with the second molars erupted completely were included. The 2 radiographic techniques were used to observe if the roots of maxillary teeth project into the sinus, including canine, the first premolar, the second premolar, the first molar and the second molar. With CBCT as a gold standard, the diagnostic sensitivity and specificity of panoramic radiography were evaluated, as well as the accuracy, prevalence, positive likehood ratio, and negtive likehood ratio. RESULTS: The sensitivity for canine, the first premolar, the second premolar, the first molar, and the second molar was 100%, 100%, 96%, 99%, and 96%, respectively. The specificity for canine, the first premolar the second premolar, the first molar, and the second molar was 94%, 92%, 84%, 67%, and 67%, respectively. CONCLUSIONS: Panoramic radiography has a high diagnostic sensitivity in detection of the teeth roots projecting into the maxillary sinus for maxillary teeth. However, it can't afford sufficient proof for orthodontic anchorage design because of low specificity, especially for the second premolar, the first molar and the second molar.

[Cephalometric evaluation of the effects of pendulum appliance on various vertical growth patterns].

OBJECTIVE: The aim of this study was to investigate the effects of the pendulum appliance in treating dental Class II patients with various vertical growth patterns. METHODS: The samples (n = 30) were divided into three groups equally based on their FMA. Pretreatment and post-treatment cephalometric radiographs were taken to measure the changes. RESULTS: The amount of upper molar distalization in the low-angle group was the fewest, and that in the high-angle group was the most. Upper molars had been intruded insignificantly. The amount of anchorage loss at the first premolars and overjet increased at incisors was different in the three groups. The biggest change happened in the low-angle group, and the smallest in the high-angle group. CONCLUSION: The results of this study showed that pendulum appliance could move the upper molars distally in a short period of time. The upper molars in different groups were intruded insignificantly. Pendulum appliance could be used to move the upper molars distally in high-angle cases.