Inactivation of Mst/Nrf2/Keap1 signaling flexibly mitigates MAPK/NQO-HO1 activation in the reproductive axis of experimental fluorosis.

Fluoride induced reprotoxicity through oxidative stress-mediated reproductive cell death. Hence, the current study evaluated the importance of the MST/Nrf2/MAPK/NQO-HO1 signaling pathway in fluorosis-induced reproductive toxicity. For this purpose, the reproductive toxicity of sodium fluoride (NaF) at physiological, biochemical, and intracellular levels was evaluated. In-vivo, NaF at 100 mg/L instigated physiological dysfunction, morphological, stereological, and structural injuries in the gut-gonadal axis of fluorosis mice through weakening the antioxidant signaling, Nrf2/HO-1/NQO1signaling pathway, causing the gut-gonadal barrier disintegrated via oxidative stress-induced inflammation, mitochondrial damage, apoptosis, and autophagy. Similar trends were also observed in-vitro in the isolated Leydig cells (LCs) challenging with 20 mg/L NaF. Henceforth, activating the cellular antioxidant signaling pathway, Nrf2/HO-1/NQO1, inactivating autophagy and apoptosis, or attenuating lipopolysaccharide (LPS) can be the theoretical basis and valuable therapeutic targets for coping with NaF-induced reproductive toxicity.

A magnetic protein biocompass.

The notion that animals can detect the Earth's magnetic field was once ridiculed, but is now well established. Yet the biological nature of such magnetosensing phenomenon remains unknown. Here, we report a putative magnetic receptor (Drosophila CG8198, here named MagR) and a multimeric magnetosensing rod-like protein complex, identified by theoretical postulation and genome-wide screening, and validated with cellular, biochemical, structural and biophysical methods. The magnetosensing complex consists of the identified putative magnetoreceptor and known magnetoreception-related photoreceptor cryptochromes (Cry), has the attributes of both Cry- and iron-based systems, and exhibits spontaneous alignment in magnetic fields, including that of the Earth. Such a protein complex may form the basis of magnetoreception in animals, and may lead to applications across multiple fields.

[Three-dimensional comparative study on the stability of bimaxillary simultaneous genioplasty and simple genioplasty].

PURPOSE: To establish a three-dimensional method to evaluate whether there is a difference in stability between bimaxillary simultaneous genioplasty and simple genioplasty. METHODS: This study was a retrospective study. Sixty patients who underwent genioplasty were selected. They were divided into bimaxillary simultaneous genioplasty group (n=30) and simple genioplasty group (n=30). The spiral CT data of patients at 2 months before operation (T0), 7 days after operation (T1) and 12 months after operation (T2) were collected, reconstructed and separated, and the three-dimensional model of maxilla and mandible was obtained. A three-dimensional analysis method of stability was established by 3D-matching. Recurrences in three-dimensional space 12 months after surgery were analyzed in two groups of patients. Statistical analysis of the data was performed with SPSS 26.0 software package. RESULTS: In simple genioplasty, the maximum amount of the chin recurrence was sagittal backward recurrence (0.54±0.38) mm, and the sagittal recurrence rate was 12.27%. In bimaxillary simultaneous genioplasty, the maximum amount of the chin recurrence was sagittal backward recurrence (0.60±0.31) mm, and the sagittal recurrence rate was 12.96%. Rotation occurred in both groups 12 months after operation, which was 1.98±2.70° in the simple genioplasty group and 1.01±1.61° in the bimaxillary simultaneous genioplasty group(P＜0.05). There was no significant difference in the sagittal movement of the chin between the two groups, and in the sagittal recurrence(P＞0.05). CONCLUSIONS: The three-dimensional method established in this study can be used to evaluate the stability after genioplasty. The recurrence after genioplasty mainly occurred in the sagittal direction. The rotation trend of chin after genioplasty is worthy of attention. There was no increased risk for bimaxillary simultaneous genioplasty.

Robust ultraclean atomically thin membranes for atomic-resolution electron microscopy.

The fast development of high-resolution electron microscopy (EM) demands a background-noise-free substrate to support the specimens, where atomically thin graphene membranes can serve as an ideal candidate. Yet the preparation of robust and ultraclean graphene EM grids remains challenging. Here we present a polymer- and transfer-free direct-etching method for batch fabrication of robust ultraclean graphene grids through membrane tension modulation. Loading samples on such graphene grids enables the detection of single metal atoms and atomic-resolution imaging of the iron core of ferritin molecules at both room- and cryo-temperature. The same kind of hydrophilic graphene grid allows the formation of ultrathin vitrified ice layer embedded most protein particles at the graphene-water interface, which facilitates cryo-EM 3D reconstruction of archaea 20S proteasomes at a record high resolution of ~2.36 Å. Our results demonstrate the significant improvements in image quality using the graphene grids and expand the scope of EM imaging.

Management strategy in patient with familial gigantiform cementoma: A case report and analysis of the literature.

RATIONALE: Familial gigantiform cementoma (FGC) is a rare benign autosomal dominant fibrocemento-osseous lesion generally limited to the facial bones, typically in the anterior portion of the mandible; it is often associated with abnormalities of the long bones and prepubertal pathologic fractures. Owing to the small number of such patients, a uniform treatment criterion has not been established. This paper presents a patient with FGC who was treated in our department, and offers a systematic review of the patients reported in the literature. Our aim was to explore the treatment strategy for patients with FGC. PATIENT CONCERNS: Our patient, a 13-year-old boy, presented with a painless enlargement of the mandible first noted 2 years earlier. It had grown rapidly over the preceding 8 months, affecting both his appearance and ability to chew. DIAGNOSIS: Based on the pathologic, clinical, and radiographic features, FGC was diagnosed. INTERVENTIONS: Mandibuloectomy was performed. The mandibular defect was immediately reconstructed with his right vascularized iliac crest flap. At the same time, a PubMed search was conducted to identify studies reporting on other patients with FGC. OUTCOMES: A 3-dimensional computed tomography (3D-CT) scan demonstrated appropriate height of the new alveolar bone. Follow-up results showed recovery of the patient's appearance and mandibular function. He was free of recurrence at 4-year follow-up. LESSONS: FGC is a rare benign fibrocemento-osseous lesion of the jaws that can cause severe facial deformity. Incomplete removal leads to more rapid growth of the residual lesion. Therefore, extensive resection is a suitable strategy to avoid recurrence. Defects of the facial bones found intraoperatively should be repaired with resort to an appropriate donor site. However, it is important to be aware that patients with FGC always have concomitant abnormalities of skeletal metabolism and structure, as well as a vulnerability to fractures of the long bones of the lower extremity. Therefore, the optimal management strategy should include a review of treatment options for other patients as reported in the literature. An optimal protocol can not only provide sufficient high-quality bone suitable for the reconstruction of bone defects, but also minimize complications and maximize quality of life.

Health safety of main water pipe materials supplied in China market.

OBJECTIVE: To assess the health safety of copper, steel and plastic water pipes by field water quality investigations. METHODS: Four consumers were randomly selected for each type of water pipes. Two consumers of every type of the water pipes had used the water pipes for more than 1 year and the other 2 consumers had used the water pipes for less than 3 months. The terminal volume of tap water in copper and steel water pipes should be not less than 0.1 liter, whereas that in plastic water pipes should be not less than 1 liter. RESULTS: The mean values of the experimental results in the second field water quality investigation of the copper and steel water pipes met the Sanitary Standards for Drinking Water Quality. The items of water sample of the plastic water pipes met the requirements of the Sanitary Standards for Drinking Water Quality. CONCLUSION: Copper, steel, and plastic pipes can be used as drinking water pipes.

[Cone-beam computed tomography evaluation of short- and long-term airway changes in patients with skeletal Class â ¢ malocclusion treated by orthodontic therapy and bimaxillary surgery with or without mandibular setback surgery].

PURPOSE: To evaluate the short-term and long-term effects of pharyngeal airway in skeletal Class Ⅲ malocclusion patients who underwent bimaxillary surgery or isolated mandibular setback-orthodontic treatment. METHODS: The sample included 54 patients (28 males, 26 females) who were diagnosed with skeletal Class Ⅲ malocclusion. Patents in group A (n=28) underwent mandibular setback surgery and orthodontic treatment. Cone-beam CT (CBCT) was taken at one week before treatment (T0), 6 months (T1) and 3 years after surgery (T2).Patents in group B(n=26) underwent Le Fort I procedures with bilateral split ramus osteotomies-orthodontic treatment; The raw data reconstructed into 3D model. Sagittal and transversal measurements, cross sectional areas, partial and total volumes were evaluated. The data were statistically analyzed using SPSS 17.0 software package to determine the changes in each group. RESULTS: Six months after surgery, the sagittal diameters and cross sectional areas of each section in group A were significantly decreased (P<0.05). Oropharyngeal volume, hypopharyngeal volume and total volume were significantly narrowed (P<0.01). Three years after surgery, only sagittal and cross sectional areas in the first cervical vertebra plane were returned to the original levels (T2-T0：P>0.05, T2-T1: P<0.05). In group B, the sagittal diameters and cross sectional areas of each section (except CV1 plane) were significantly decreased(P<0.05) 3 years after surgery, but most measurements returned to the original levels. CONCLUSIONS: Pharyngeal airway space decreased after combined therapy in the short term; however, relapse occurred and not to its original position in the long term.

A new linear bismuth coordination polymer based on 1,10-phenanthroline-2,9-dicarboxylic acid: ionothermal synthesis, crystal structure and fluorescence properties.

A new linear bismuth(III) coordination polymer, catena-poly[[chloridobismuth(III)]-µ3-1,10-phenanthroline-2,9-dicarboxylato-κ(6)O(2):O(2),N(1),N(10),O(9):O(9)], [Bi(C14H6N2O4)Cl]n, has been obtained by an ionothermal method and characterized by elemental analysis, energy-dispersive X-ray spectroscopy, IR spectroscopy, thermal stability studies and single-crystal X-ray diffraction. The structure is constructed by Bi(C14H6N2O4)Cl fragments in which each Bi(III) centre is seven-coordinated by one Cl atom, four O atoms and two N atoms. The coordination geometry of the Bi(III) cation is distorted pentagonal-bipyramidal (BiO4N2Cl), with one bridging carboxylate O atom and one Cl atom located in the axial positions. The Bi(C14H6N2O4)Cl fragments are further extended into a one-dimensional linear polymeric structure via subsequent but different centres of symmetry (bridging carboxylate O atoms). Neighbouring linear chains are assembled via weak C-H···O and C-H···Cl hydrogen bonds, forming a three-dimensional supramolecular architecture. Intermolecular π-π stacking interactions are observed, with centroid-to-centroid distances of 3.678 (4) Å, which further stabilize the structure. In addition, the solid-state fluorescence properties of the title coordination polymer were investigated.

Alveolar soft part sarcoma of the oral and maxillofacial region: clinical analysis in a series of 18 patients.

OBJECTIVES: To summarize the clinical features, diagnosis, treatment strategies, and prognosis of alveolar soft part sarcoma (ASPS) of the oral and maxillofacial region. STUDY DESIGN: We performed a retrospective study in a consecutive series of 18 patients with ASPS of the oral and maxillofacial region between 1995 and 2013. Demographic characteristics, tumor sizes, sites, tumor metastasis, diagnosis, treatments, and overall follow-ups were documented. RESULTS: The 18 patients were diagnosed pathologically with primary tumor developed on the tongue (10), the cheek (5), the pharynx (1), and the gingiva (2) with an average tumor size of 4 cm. At the latest follow-up, 1 patient with lung metastases survived for 23 months; 1 died 3 months after the confirmation of local recurrence and multiple pulmonary metastases; the rest of the patients were disease free and remained in good health. CONCLUSIONS: ASPS of the oral and maxillofacial region appears to have special clinical characteristics.

SNARE proteins: one to fuse and three to keep the nascent fusion pore open.

Neurotransmitters are released through nascent fusion pores, which ordinarily dilate after bilayer fusion, preventing consistent biochemical studies. We used lipid bilayer nanodiscs as fusion partners; their rigid protein framework prevents dilation and reveals properties of the fusion pore induced by SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor). We found that although only one SNARE per nanodisc is required for maximum rates of bilayer fusion, efficient release of content on the physiologically relevant time scale of synaptic transmission apparently requires three or more SNARE complexes (SNAREpins) and the native transmembrane domain of vesicle-associated membrane protein 2 (VAMP2). We suggest that several SNAREpins simultaneously zippering their SNARE transmembrane helices within the freshly fused bilayers provide a radial force that prevents the nascent pore from resealing during synchronous neurotransmitter release.

[Three-dimensional analysis of pharyngeal airway in skeletal Class III patients after sagittal split ramus osteotomy].

OBJECTIVE: To analyze the three-dimensional changes of pharyngeal airway in patients with skeletal Class III malocclusion after the combined orthodontic and orthognathic treatment. METHODS: Twenty patients (9 males, 11 females) and 40 subjects with normal occlusion were involved in the study. Cone-beam computed tomography (CBCT) were performed on patients one week and six months after treatment. Raw data were reconstructed into three-dimensional model and sagittal and transversal measurements, cross sectional areas, partial and total volumes were computed. RESULTS: After treatment, the sagittal diameters of each section were significantly reduced by (2.7 ± 3.5), (3.0 ± 3.8), (2.7 ± 3.3) mm, respectively (P < 0.05). The transversal diameter of laryngopharyngeal airway constricted significantly by (4.8 ± 4.1) mm (P < 0.05). Cross sectional areas and volumes of each part in patients after surgery were significantly narrower compared with those of the controls. CONCLUSIONS: After combined therapy the pharyngeal airway space decreased.

Simulations of tubulin sheet polymers as possible structural intermediates in microtubule assembly.

The microtubule assembly process has been extensively studied, but the underlying molecular mechanism remains poorly understood. The structure of an artificially generated sheet polymer that alternates two types of lateral contacts and that directly converts into microtubules, has been proposed to correspond to the intermediate sheet structure observed during microtubule assembly. We have studied the self-assembly process of GMPCPP tubulins into sheet and microtubule structures using thermodynamic analysis and stochastic simulations. With the novel assumptions that tubulins can laterally interact in two different forms, and allosterically affect neighboring lateral interactions, we can explain existing experimental observations. At low temperature, the allosteric effect results in the observed sheet structure with alternating lateral interactions as the thermodynamically most stable form. At normal microtubule assembly temperature, our work indicates that a class of sheet structures resembling those observed at low temperature is transiently trapped as an intermediate during the assembly process. This work may shed light on the tubulin molecular interactions, and the role of sheet formation during microtubule assembly.

[Research of soluble interleukin-1 and tumor necrosis factor receptor treatment in orthodontic tooth movement in rats].

OBJECTIVE: To investigate the effects of local injections of recombinant soluble human receptors on experimental orthodontic tooth movement in the rat. METHODS: 64 male Sprague-Dawley rats were observed. Starting at day 1, three groups of animals each received local injections of soluble interleukin-1 receptor II (sIL-1-R II ), soluble' tumor necrosis factor receptor I (sTNF-R I ) and their combinations. One group served as the control. The amount of tooth movement was recorded and selected tissue sections were stained with hematoxylin-eosin (HE) to observe the histological morphologic alterations of the periodontal tissues and also were stained with tartrate-resistant acid phosphatase (TRAP) histochemistry to analyze the changes of the amount and distribution of osteoclasts and odontoclasts. RESULTS: The time-depended histomorphology changes in each receptor group were similar to those in the control group, but the resorption of alveolar bone was slighter at each time point and the surface of root appeared no or a few cement resorption signs. On day 14, the TRAP-positive cells on the surface of alveolar bone and root were reduced by approximately 50% relative to those in the control group (P<0.05). Whereas statistical tests revealed there were no significant differences among the experimental groups (P>0.05). CONCLUSION: Local injections of recombinant human sIL-1-R II and sTNF-R I in the orthodontic tooth of rats could reduce the amount and velocity of orthodontic tooth movement and reduce the incidence of root resorption.

An iterative Fourier-Bessel algorithm for reconstruction of helical structures with severe Bessel overlap.

Classical Fourier-Bessel methodology fails when used to reconstruct helical structures with severe Bessel overlap on the layer lines. In the reconstruction of a peculiar type of double-layered helical tube of GDP-tubulin, we face the problem of Bessel overlap on all the layer lines due to the superposition of the Fourier components from the inner and outer layers of the tube. In order to decompose the Fourier terms of the inner and outer layers more than one image of the tubes must be combined and the orientations of their inner and outer layer helices must be determined. While there is no direct analytical method to determine these orientational parameters, we have devised an iterative Fourier-Bessel algorithm to calculate the correct orientations and thus allow us to obtain a reconstruction from multiple images of the double-layered tubes. The algorithm successfully works for the reconstruction of computer-modeled double-layered helical tubes as well as with real images obtained by cryo-electron microscopy. The algorithm has also been applied with very satisfactory results to the reconstruction of 13-protofilament microtubules, which is another helical structure that suffer Bessel overlap, suggesting its generality.

Assembly of GMPCPP-bound tubulin into helical ribbons and tubes and effect of colchicine.

Microtubule assembly and disassembly is a complex structural process that does not proceed by simple addition and subtraction of individual subunits to and from a helical polymer, as would be the case for actin and other helical assemblies. The dynamic process of microtubule growth and shrinking involves short-lasting polymer forms that differ substantially from the microtubule itself and constitute crucial assembly and disassembly intermediates. Structural characterization thus depends on the stabilization of these brief intermediates and their preservation as polymeric assemblies. This paper gives experimental details on the polymerization of GMPCPP-tubulin into low-temperature, stable polymers that we propose to correspond to the early stages in microtubule assembly, and includes new data on the effect of colchicine on GMPCPP-tubulin polymerization. Finally, we add our thoughts on the possible biological meaning of tubulin polymerization versatility.

Ring-like pore structures of SecA: implication for bacterial protein-conducting channels.

SecA, an essential component of the general protein secretion pathway of bacteria, is present in Escherichia coli as soluble and membrane-integral forms. Here we show by electron microscopy that SecA assumes two characteristic forms in the presence of phospholipid monolayers: dumbbell-shaped elongated structures and ring-like pore structures. The ring-like pore structures with diameters of 8 nm and holes of 2 nm are found only in the presence of anionic phospholipids. These ring-like pore structures with larger 3- to 6-nm holes (without staining) were also observed by atomic force microscopic examination. They do not form in solution or in the presence of uncharged phosphatidylcholine. These ring-like phospholipid-induced pore-structures may form the core of bacterial protein-conducting channels through bacterial membranes.