Characteristics of biological manganese oxides produced by manganese-oxidizing bacteria H38 and its removal mechanism of oxytetracycline.

Oxytetracycline (OTC) is widely used in clinical medicine and animal husbandry. Residual OTC can affect the normal life activities of microorganisms, animals, and plants and affect human health. Microbial remediation has become a research hotspot in the environmental field. Manganese oxidizing bacteria (MnOB) exist in nature, and the biological manganese oxides (BMO) produced by them have the characteristics of high efficiency, low cost, and environmental friendliness. However, the effect and mechanism of BMO in removing OTC are still unclear. In this study, Bacillus thuringiensis strain H38 of MnOB was obtained, and the conditions for its BMO production were optimized. The optimal conditions were determined as follows: optimal temperature = 35 °C, optimal pH = 7.5, optimal Mn(Ⅱ) initial concentration = 10 mmol/L. The results show that BMO are irregular or massive, mainly containing MnCO3, Mn2O3, and MnO2, with rich functional groups and chemical bonds. They have the characteristics of small particle size and large specific surface area. OTC (2.5 mg/L) was removed when the BMO dosage was 75 µmol/L and the solution pH was 5.0. The removal ratio was close to 100 % after 12 h of culture at 35 °C and 150 r/min. BMO can adsorb and catalyze the oxidation of OTC and can produce ·O2-, ·OH, 1O2, and Mn(Ⅲ) intermediate. Fifteen products and degradation pathways were identified, and the toxicity of most intermediates is reduced compared to OTC. The removal mechanism was preliminarily clarified. The results of this study are convenient for the practical application of BMO in OTC pollution in water and for solving the harm caused by antibiotic pollution.

Rhizosphere bacteria G-H27 significantly promoted the degradation of chlorpyrifos and fosthiazate.

Microbial remediation of polluted environments is the most promising and significant research direction in the field of bioremediation. In this study, chlorpyrifos and fosthiazate were selected as representative organophosphorus pesticides, wheat was the tested plant, and fluorescently labeled degrading Bacillus cereus G-H27 were the film-forming bacteria. Exogenous strengthening technology was used to establish degrading bacterial biofilms on the root surface of wheat. The influence of root surface-degrading bacterial biofilms on the enrichment of chlorpyrifos and fosthiazate in wheat was comprehensively evaluated. First, the fluorescently-labeled degrading bacteria G-H27 was constructed, and its film-forming ability was investigated. Second, the growth- promoting characteristics and degradation ability of the bacteria G-H27 were investigated. Finally, the degradation effect of the root surface-degrading bacterial biofilm on chlorpyrifos and fosthiazate was determined. The above research provides an important material basis and method for the bioremediation of pesticide-contaminated soil.

The Effect of Theaflavins on the Gut Microbiome and Metabolites in Diabetic Mice.

With the development of diabetes, the gut microbiome falls into a state of dysbiosis, further affecting its progression. Theaflavins (TFs), a type of tea polyphenol derivative, show anti-diabetic properties, but their effect on the gut microbiome in diabetic mice is unclear. It is unknown whether the improvement of TFs on hyperglycemia and hyperlipidemia in diabetic mice is related to gut microbiota. Therefore, in this study, different concentrations of TFs were intragastrically administered to mice with diabetes induced by a high-fat-diet to investigate their effects on blood glucose, blood lipid, and the gut microbiome in diabetic mice, and the plausible mechanism underlying improvement in diabetes was explored from the perspective of the gut microbiome. The results showed that the TFs intervention significantly improved the hyperglycemia and hyperlipidemia of diabetic mice and affected the structure of the gut microbiome by promoting the growth of bacteria positively related to diabetes and inhibiting those negatively related to diabetes. The changes in short-chain fatty acids in mice with diabetes and functional prediction analysis suggested that TFs may affect carbohydrate metabolism and lipid metabolism by regulating the gut microbiome. These findings emphasize the ability of TFs to shape the diversity and structure of the gut microbiome in mice with diabetes induced by a high-fat diet combined with streptozotocin and have practical implications for the development of functional foods with TFs.

Biodegradation mechanism of chlorpyrifos by Bacillus sp. H27: Degradation enzymes, products, pathways and whole genome sequencing analysis.

Chlorpyrifos (CP) is a pesticide widely used in agricultural production. However, excessive use of CP is risky for human health and the ecological environment. Microbial remediation has become a research hotspot of environmental pollution control. In this study, the effective CP-degrading strain H27 (Bacillus cereus) was screened from farmland soil, and the degradation ratio was more than 80%. Then, the degradation mechanism was discussed in terms of enzymes, pathways, products and genes, and the mechanism was improved in terms of cell motility, secretory transport system and biofilm formation. The key CP-degrading enzymes were mainly intracellular enzymes (IE), and the degradation ratio reached 49.6% within 30 min. The optimal pH for IE was 7.0, and the optimal temperature was 25 °C. Using DFT and HPLC‒MS analysis, it was found that degradation mainly involved oxidation, hydrolysis and other reactions, and 3 degradation pathways and 14 products were identified, among which TCP (3,5,6-trichloro-2-pyridinol) was the main primary degradation product in addition to small molecules such as CO2 and H2O. Finally, the whole genome of strain H27 was sequenced, and the related degrading genes and enzymes were investigated to improve the metabolic pathways. Strain H27 had perfect genes related to flagellar assembly and chemotaxis and tended to tolerate CP. Moreover, it can secrete esterase, phosphatase and other substances, which can form biofilms and degrade CP in the environment. In addition, CP enters the cell under the action of permeases or transporters, and it is metabolized by IE. The degradation mechanism of CP by strain H27 is speculated in this study, which provided a theoretical basis for enriching CP-degrading bacteria resources, improving degradation metabolic pathways and mechanisms, and applying strain H27 to environmental pollution remediation.

Classification of mild Parkinson's disease: data augmentation of time-series gait data obtained via inertial measurement units.

Data-augmentation methods have emerged as a viable approach for improving the state-of-the-art performances for classifying mild Parkinson's disease using deep learning with time-series data from an inertial measurement unit, considering the limited amount of training datasets available in the medical field. This study investigated effective data-augmentation methods to classify mild Parkinson's disease and healthy participants with deep learning using a time-series gait dataset recorded via a shank-worn inertial measurement unit. Four magnitude-domain-transformation and three time-domain-transformation data-augmentation methods, and four methods involving mixtures of the aforementioned methods were applied to a representative convolutional neural network for the classification, and their performances were compared. In terms of data-augmentation, compared with baseline classification accuracy without data-augmentation, the magnitude-domain transformation performed better than the time-domain transformation and mixed-data augmentation. In the magnitude-domain transformation, the rotation method significantly contributed to the best performance improvement, yielding accuracy and F1-score improvements of 5.5 and 5.9%, respectively. The augmented data could be varied while maintaining the features of the time-series data obtained via the sensor for detecting mild Parkinson's in gait; this data attribute may have caused the aforementioned trend. Notably, the selection of appropriate data extensions will help improve the classification performance for mild Parkinson's disease.

Determination of the Absorption, Translocation, and Distribution of Imidacloprid in Wheat.

Neonicotinoids, a class of insecticides, are widely used because of their novel modes of action, high insecticidal activity, and strong root uptake. Imidacloprid, the most widely used insecticide worldwide, is a representative first-generation neonicotinoid and is used in pest control for crops, vegetables, and fruit trees. With such a broad application of imidacloprid, its residue in crops has attracted increasing scrutiny. In the present study, 15 wheat seedlings were placed in a culture medium containing 0.5 mg/L or 5 mg/L imidacloprid for hydroculture. The content of imidacloprid in the wheat roots and leaves was determined after 1 day, 2 days, and 3 days of hydroculture to explore the migration and distribution of imidacloprid in wheat. The results showed that imidacloprid was detected both in the roots and leaves of the wheat plant, and the content of imidacloprid in the roots was higher than that in the leaves. Furthermore, the imidacloprid concentration in the wheat increased with increasing exposure time. After 3 days of exposure, the roots and leaves of the wheat in the 0.5 mg/L treatment group contained 4.55 mg/kg ± 1.45 mg/kg and 1.30 mg/kg ± 0.08 mg/kg imidacloprid, respectively, while the roots and leaves of the 5 mg/L treatment group contained 42.5 mg/kg ± 0.62 mg/kg and 8.71 mg/kg ± 0.14 mg/kg imidacloprid, respectively. The results from the present study allow for a better understanding of pesticide residues in crops and provide a data reference for the environmental risk assessment of pesticides.

Structural Characteristics and Multiple Bioactivities of Volvariella volvacea Polysaccharide Extracts: The Role of Extractive Solvents.

The chemical structures and functional properties of plant-based polysaccharides are critically influenced by extractive solvents, but their roles are not clear. In this study, the structural characteristics and multiple bioactivities of Volvariella volvacea polysaccharides (VVPs) subjected to water (VVP-W), alkalis (sodium hydroxide, VVP-A), and acids (citric acid, VVP-C) as extractive solvents are investigated systematically. Of the above three polysaccharides, VVP-W exhibited the highest molecular weights, apparent viscosity, and viscoelastic properties. Functional analyses revealed that VVP-C had an excellent water-holding capacity, foaming properties, and emulsifying capacity, while VVP-A exhibited a promising oil-holding capacity. Moreover, VVP-C displayed strong inhibitory effects on α-amylase and α-glucosidase, which could be attributed to its content of total phenolics, proteins, and molecular weights. These findings have important implications for selecting the appropriate extraction techniques to obtain functional polysaccharides with targeted bioactive properties as food additives.

Advanced Glycation End Products, Bone Health, and Diabetes Mellitus.

Advanced glycation end products (AGEs), the compounds resulting from the non-enzymatic glycosylation between reducing sugars and proteins, are derived from food or produced de novo. Over time, more and more endogenous and exogenous AGEs accumulate in various organs such as the liver, kidneys, muscle, and bone, threatening human health. Among these organs, bone is most widely reported. AGEs accumulating in bone reduce bone strength by participating in bone structure formation and breaking bone homeostasis by binding their receptors to alter the proliferation, differentiation, and apoptosis of cells involved in bone remodeling. In this review, we summarize the research about the effects of AGEs on bone health and highlight their associations with bone health in diabetes patients to provide some clues toward the discovery of new treatment and prevention strategies for bone-related diseases caused by AGEs.

The Protective Effect of Theaflavins on the Kidney of Mice with Type II Diabetes Mellitus.

Diabetic nephropathy, primarily caused by advanced glycation end products (AGEs), is a serious complication resulting from type 2 diabetes mellitus (T2DM). Reportedly, theaflavins (TFs) can improve diabetic nephropathy; however, the underlying molecular mechanism is not fully clear. In this study, T2DM mice were treated with different concentrations of TFs by gavage for 10 weeks to investigate the effect of TFs on diabetic nephropathy and their potential molecular mechanism of action. Biochemical and pathological analysis showed that the TFs effectively improved blood glucose, insulin resistance, kidney function, and other symptoms in diabetic mice. The mechanism studies indicated that TFs inhibited the formation of AGEs, thereby inhibiting the activation of the MAPK/NF-κB signaling pathway. Therefore, our study suggested that TFs improved diabetic nephropathy by inhibiting the formation of AGEs.

Long-term clinical observation of patients with acute and chronic complete spinal cord injury after transplantation of NeuroRegen scaffold.

Spinal cord injury (SCI) often results in an inhibitory environment at the injury site. In our previous studies, transplantation of a scaffold combined with stem cells was proven to induce neural regeneration in animal models of complete SCI. Based on these preclinical studies, collagen scaffolds loaded with the patients' own bone marrow mononuclear cells or human umbilical cord mesenchymal stem cells were transplanted into SCI patients. Fifteen patients with acute complete SCI and 51 patients with chronic complete SCI were enrolled and followed up for 2 to 5 years. No serious adverse events related to functional scaffold transplantation were observed. Among the patients with acute SCI, five patients achieved expansion of their sensory positions and six patients recovered sensation in the bowel or bladder. Additionally, four patients regained voluntary walking ability accompanied by reconnection of neural signal transduction. Among patients with chronic SCI, 16 patients achieved expansion of their sensation level and 30 patients experienced enhanced reflexive defecation sensation or increased skin sweating below the injury site. Nearly half of the patients with chronic cervical SCI developed enhanced finger activity. These long-term follow-up results suggest that functional scaffold transplantation may represent a feasible treatment for patients with complete SCI.

Diffusion tensor imaging predicting neurological repair of spinal cord injury with transplanting collagen/chitosan scaffold binding bFGF.

Prognosis and treatment evaluation of spinal cord injury (SCI) are still in the long-term research stage. Prognostic factors for SCI treatment need effective biomarker to assess therapeutic effect. Quantitative diffusion tensor imaging (DTI) may become a potential indicators for assessing SCI repair. However, its correlation with the results of locomotor function recovery and tissue repair has not been carefully studied. The aim of this study was to use quantitative DTI to predict neurological repair of SCI with transplanting collagen/chitosan scaffold binding basic fibroblast growth factor (bFGF). To achieve our research goals, T10 complete transection SCI model was established. Then collagen/chitosan mixture adsorbed with bFGF (CCS/bFGF) were implanted into rats with SCI. At 8 weeks after modeling, implanting CCS/bFGF demonstrated more significant improvements in locomotor function according to Basso-Beattie-Bresnahan (BBB) score, inclined-grid climbing test, and electrophysiological examinations. DTI was carried out to evaluate the repair of axons by diffusion tensor tractgraphy (DTT), fractional anisotropy (FA) and apparent diffusion coefficient (ADC), a numerical measure of relative white matter from the rostral to the caudal. Parallel to locomotor function recovery, the CCS/bFGF group could significantly promote the regeneration of nerve fibers tracts according to DTT, magnetic resonance imaging (MRI), Bielschowsky's silver staining and immunofluorescence staining. Positive correlations between imaging and locomotor function or histology were found at all locations from the rostral to the caudal (P < 0.0001). These results demonstrated that DTI might be used as an effective predictor for evaluating neurological repair after SCI in experimental trails and clinical cases.

Significant Improvement of Acute Complete Spinal Cord Injury Patients Diagnosed by a Combined Criteria Implanted with NeuroRegen Scaffolds and Mesenchymal Stem Cells.

Stem cells and biomaterials transplantation hold a promising treatment for functional recovery in spinal cord injury (SCI) animal models. However, the functional recovery of complete SCI patients was still a huge challenge in clinic. Additionally, there is no clinical standard procedure available to diagnose precisely an acute patient as complete SCI. Here, two acute SCI patients, with injury at thoracic 11 (T11) and cervical 4 (C4) level respectively, were judged as complete injury by a stricter method combined with American Spinal Injury Association (ASIA) Impairment Scale, magnetic resonance imaging (MRI) and nerve electrophysiology. Collagen scaffolds, named NeuroRegen scaffolds, with human umbilical cord mesenchymal stem cells (MSCs) were transplanted into the injury site. During 1 year follow up, no obvious adverse symptoms related to the functional scaffolds implantation were found after treatment. The recovery of the sensory and motor functions was observed in the two patients. The sensory level expanded below the injury level, and the patients regained the sense function in bowel and bladder. The thoracic SCI patient could walk voluntary with the hip under the help of brace. The cervical SCI patient could raise his lower legs against the gravity in the wheelchair and shake his toes under control. The injury status of the two patients was improved from ASIA A complete injury to ASIA C incomplete injury. Furthermore, the improvement of sensory and motor functions was accompanied with the recovery of the interrupted neural conduction. These results showed that the supraspinal control of movements below the injury was regained by functional scaffolds implantation in the two patients who were judged as the complete injury with combined criteria, it suggested that functional scaffolds transplantation could serve as an effective treatment for acute complete SCI patients.

Clinical Study of NeuroRegen Scaffold Combined With Human Mesenchymal Stem Cells for the Repair of Chronic Complete Spinal Cord Injury.

Regeneration of damaged neurons and recovery of sensation and motor function after complete spinal cord injury (SCI) are challenging. We previously developed a collagen scaffold, NeuroRegen, to promote axonal growth along collagen fibers and inhibit glial scar formation after SCI. When functionalized with multiple biomolecules, this scaffold promoted neurological regeneration and functional recovery in animals with SCI. In this study, eight patients with chronic complete SCI were enrolled to examine the safety and efficacy of implanting NeuroRegen scaffold with human umbilical cord mesenchymal stem cells (hUCB-MSCs). Using intraoperative neurophysiological monitoring, we identified and surgically resected scar tissues to eliminate the inhibitory effect of glial scarring on nerve regeneration. We then implanted NeuroRegen scaffold loaded with hUCB-MSCs into the resection sites. No adverse events (infection, fever, headache, allergic reaction, shock, perioperative complications, aggravation of neurological status, or cancer) were observed during 1 year of follow-up. Primary efficacy outcomes, including expansion of sensation level and motor-evoked potential (MEP)-responsive area, increased finger activity, enhanced trunk stability, defecation sensation, and autonomic neural function recovery, were observed in some patients. Our findings suggest that combined application of NeuroRegen scaffold and hUCB-MSCs is safe and feasible for clinical therapy in patients with chronic SCI. Our study suggests that construction of a regenerative microenvironment using a scaffold-based strategy may be a possible future approach to SCI repair.

Collagen/heparin sulfate scaffolds fabricated by a 3D bioprinter improved mechanical properties and neurological function after spinal cord injury in rats.

Effective treatments promoting axonal regeneration and functional recovery for spinal cord injury (SCI) are still in the early stages of development. Most approaches have been focused on providing supportive substrates for guiding neurons and overcoming the physical and chemical barriers to healing that arise after SCI. Although collagen has become a promising natural substrate with good compatibility, its low mechanical properties restrict its potential applications. The mechanical properties mainly rely on the composition and pore structure of scaffolds. For the composition of a scaffold, we used heparin sulfate to react with collagen by crosslinking. For the structure, we adopted a three-dimensional (3D) printing technology to fabricate a scaffold with a uniform pore distributions. We observed that the internal structure of the scaffold printed with a 3D bioprinter was regular and porous. We also found that both the compression modulus and strengths of the scaffold were significantly enhanced by the collagen/heparin sulfate composition compared to a collagen scaffold. Meanwhile, the collagen/heparin sulfate scaffold presented good biocompatibility when it was co-cultured with neural stem cells in vitro. We also demonstrated that heparin sulfate modification significantly improved bFGF immobilization and absorption to the collagen by examining the release kinetics of bFGF from scaffolds. Two months after implantating the scaffold into transection lesions in T10 of the spinal cord in rats, the collagen/heparin sulfate group demonstrated significant recovery of locomotor function and according to electrophysiological examinations. Parallel to functional recovery, collagen/heparin sulfate treatment further ameliorated the pathological process and markedly increased the number of neurofilament (NF) positive cells compared to collagen treatment alone. These data suggested that a collagen/heparin sulfate scaffold fabricated by a 3D bioprinter could enhance the mechanical properties of collagen and provide continuous guidance channels for axons, which would improve the neurological function after SCI. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1324-1332, 2017.

One-year clinical study of NeuroRegen scaffold implantation following scar resection in complete chronic spinal cord injury patients.

The objective of this clinical study was to assess the safety and feasibility of the collagen scaffold, NeuroRegen scaffold, one year after scar tissue resection and implantation. Scar tissue is a physical and chemical barrier that prevents neural regeneration. However, identification of scar tissue is still a major challenge. In this study, the nerve electrophysiology method was used to distinguish scar tissue from normal neural tissue, and then different lengths of scars ranging from 0.5-4.5 cm were surgically resected in five complete chronic spinal cord injury (SCI) patients. The NeuroRegen scaffold along with autologous bone marrow mononuclear cells (BMMCs), which have been proven to promote neural regeneration and SCI recovery in animal models, were transplanted into the gap in the spinal cord following scar tissue resection. No obvious adverse effects related to scar resection or NeuroRegen scaffold transplantation were observed immediately after surgery or at the 12-month follow-up. In addition, patients showed partially autonomic nervous function improvement, and the recovery of somatosensory evoked potentials (SSEP) from the lower limbs was also detected. The results indicate that scar resection and NeuroRegen scaffold transplantation could be a promising clinical approach to treating SCI.

[Effect of Panax NotoginSeng Saponins on motor evoked potentials of spinal cord injured rats with motion function].

OBJECTIVE: To investigate the effect of Panax NotoginSeng Saponins(PNS) on functional recovery of rats with spinal cord injury (SCI) after exercise. METHODS: SD normal rats were randomly divided into normal control group (Normal) and control group (Sham), spinal cord injury (SCI) and spinal cord injury (SCI) + panax notoginseng saponins group (PNS) (n=8). All rats were given basso beattie bresnahan motor function score (BBB) and motor evoked potentials (MEP) examination to observe rat hind limb motor function recovery before operation and 1,3,7,14,21,28 days after operation. RESULTS: After operation, the BBB scores of Sham group, PNS group, SCI group were lower than that of normal; MEP amplitude was lower than that of normal group; the incubation time was prolonged compared with that in normal group. In PNS group compared with that in the SCI group, BBB scores at 7,14,21 and 28 days was significantly different(P<0.05). There were significant differences in the latency (Lat) and amplitude(Amp) of MEP within PNA subgroups or between the PNS and the SCI groups at 7,14,21,28 days(P<0.05). CONCLUSIONS: PNS can promote the recovery of motor function after SCI in rats.