BACKGROUND: The treatments of knee osteoarthritis are mainly to relieve the symptoms, and it is difficult to be cured. Exercise therapy is denominated as a designed and ruled plan of physical activities to get some specific treated goals and aimed at the recovery of normal musculoskeletal function and reduction of the pain caused by diseases or body injuries. The research of exercise therapy in prevention and treatment of knee osteoarthritis has different opinions. OBJECTIVE: To discuss the critical factors influencing exercise therapy in the prevention and treatment of knee osteoarthritis, and to provide reference for exercise therapy in preventing and treating knee osteoarthritis. METHODS: A computer-based retrieval of CNKI and PubMed databases was performed for the articles published before January 2019. The keywords were “exercise therapy, knee osteoarthritis, prevention and treatment” in Chinese and English, respectively. The articles concerning exercise therapy effect on knee osteoarthritis were included for analysis based on inclusion and exclusion criteria. RESULTS AND CONCLUSION: (1) Exercise therapy should be begun as early as possible, and at the early period, we should pay attention to the angle of knee joint injury, and increase the intensity gradually, such as from non-weight training to weight training. (2) The middle-low intensity exercise therapy is recommended, and over-training should be avoided, especially for those who have cartilage wear.

Objective To study the clinical characteristics,pathological type,diagnosis,treatment and follow-up result of the primary tumors of the sacrum.Methods The cases of 18 patients with primary tumors of the sacrum were treated by operation(12 cases with chordoma,1 case with osteosarcoma,5 cases with giant cell tumor of bone),patients with chordoma performed by radiotherapy after operation,and all patients had been followed up for 4～8 years.Results 15 patients were cured and 3 patients were recurred after operation.Conclusions Chordoma is the most frequent tumor in primary sacrum tumor.This kind of tumor should be treated by surgical and other assist methods.

Objective: To evaluate the influence of extraction solvents on antioxidant and antimicrobial activities of the pulp and seed of Anisophyllea laurina R. Br. ex Sabine fruits. Methods: The antibacterial activities of pulp and seed extracts were tested by using disk diffusion method against eight bacterial strains and three fungal strains. Total phenolic, flavonoid, monomeric anthocyanin and tannin contents, and antioxidant activities were determined by spectrometric methods. Results: The antioxidant analysis of pulp extract revealed the strong radical scavenging capacity and total phenolic content (4. 329.66 mg of gallic acid/100 g), while seed extract showed the high antioxidant activity and total tannin content (5. 326.78 mg catechin equivalent/100 g). Antibacterial and antifungal activities of methanol and ethanol extracts exhibited potent growth inhibitory activity against Aeromonas hydrophila, Bacillus subtilis, Escherichia coli O157:H7, Pseudomonas aeruginosa, Salmonella Typhimurium and Staphylococcus aureus ATCC 6538 with minimum inhibitory concentration values ranged from 125 to 250 μg/mL. However, seed extract had the strongest potential activity against Aspergillus niger and Candida albicans with minimum inhibitory concentration value of 500 μg/mL compared to pulp extract. Conclusions: Our results therefore demonstrated that ethanol and methanol extractions were more efficient in extracting antioxidants and bioactive compound in pulp and seed. These results support that these plant extracts can be used for the treatment of bacterial infections.

Self-assembling amphipathic peptides (SAPs) have alternating hydrophilic and hydrophobic residues and can affect the thermal stabilities and catalytic properties of the fused enzymes. In this study, a novel multifunctional tag, S1vw (HNANARARHNANARARHNANARARHNARARAR) was developed to modify fused enzymes. After fusing S1vw at the enzymes/proteins N-terminus through a PT-linker, the crude enzymatic activities of polygalacturonate lyase and lipoxygenase were enhanced 3.1- and 1.89-fold, respectively, compared to the wild-type proteins. The relative fluorescence intensity of the green fluorescent protein was enhanced 16.22-fold. All the three S1vw fusions could be purified by nickel column with high purities and acceptable recovery rates. Moreover, S1vw also induced the thermostabilities enhancement of the fusions, with polygalacturonate lyase and lipoxygenase fusions exhibiting 2.16- and 3.2-fold increase compared with the corresponding wild-type, respectively. In addition, S1vw could enhance the production yield of green fluorescent protein in Escherichia coli and Bacillus subtilis while the production of GFP and its S1vw fusion changed slightly in Pichia pastoris. These results indicated that S1vw could be used as a multifunctional tag to benefit the production, thermal stability and purification of the fusion protein in prokaryotic expression system.
Escherichia coli ; Green Fluorescent Proteins ; Hydrophobic and Hydrophilic Interactions ; Peptides ; Pichia ; Recombinant Fusion Proteins ; metabolism

Human activities increase the concentration of atmospheric carbon dioxide (CO₂), which leads to global climate warming. Microbial CO₂ fixation is a promising green approach for carbon neutral. In contrast to autotrophic microorganisms, heterotrophic microorganisms are characterized by fast growth and ease of genetic modification, but the efficiency of CO₂ fixation is still limited. In the past decade, synthetic biology-based enhancement of heterotrophic CO₂ fixation has drawn wide attention, including the optimization of energy supply, modification of carboxylation pathway, and heterotrophic microorganisms-based indirect CO₂ fixation. This review focuses on the research progress in CO₂ fixation by heterotrophic microorganisms, which is expected to serve as a reference for peaking CO₂ emission and achieving carbon neutral by microbial CO₂ fixation.
Carbon Cycle ; Carbon Dioxide/metabolism* ; Heterotrophic Processes ; Humans ; Synthetic Biology

8-prenylnaringenin (8-PN) is a potent estrogen with high medicinal values. It also serves as an important precursor for many prenylated flavonoids. Microbial synthesis of 8-PN is mainly hindered by the low catalytic activity of prenyltransferases (PTS) and insufficient supply of precursors. In this work, a SfN8DT-1 from Sophora flavescens was used to improve the efficiency of (2S)-naringenin prenylation. The predicted structure of SfN8DT-1 showed that its main body is comprised of 9 α-helices and 8 loops, along with a long side chain formed by nearly 120 amino acids. SfN8DT-1 mutants with different side-chain truncated were tested in Saccharomyces cerevisiae. A mutant expressing the truncated enzyme at K62 site, designated as SfND8T-1-t62, produced the highest 8-PN titer. Molecular docking of SfN8DT-1-t62 with (2S)-naringenin and dimethylallyl diphosphate (DMAPP) showed that K185 was a potentially crucial residue. Alanine scanning within a range of 0.5 nm around these two substrates showed that the mutant K185A may decrease its affinity to substrates, which also indicated K185 was a potentially critical residue. Besides, the mutant K185W enhanced the affinity to ligands implied by the simulated saturation mutation, while the saturated mutation of K185 showed a great decrease in 8-PN production, indicating K185 is vital for the activity of SfN8DT-1. Subsequently, overexpressing the key genes of Mevalonate (MVA) pathway further improved the titer of 8-PN to 31.31 mg/L, which indicated that DMAPP supply is also a limiting factor for 8-PN synthesis. Finally, 44.92 mg/L of 8-PN was produced in a 5 L bioreactor after 120 h, which is the highest 8-PN titer reported to date.
Dimethylallyltranstransferase/metabolism* ; Flavonoids/metabolism* ; Molecular Docking Simulation ; Prenylation ; Saccharomyces cerevisiae/metabolism* ; Sophora/metabolism*

L-homophenylalanine (L-HPA) is an important non-natural amino acid that has been used as a key intermediate for the synthesis of Puli drugs for the treatment of hypertension. At present, L-HPA is synthesized using chemical methods, which has the disadvantages of expensive raw materials, tedious steps and serious pollution. Therefore, researchers have conducted in-depth research on the enzymatic production of L-HPA. This review summarizes the research progress on the enzymatic synthesis of L-HPA, including the dehydrogenase process, the transaminase process, the hydantoinase process, and the decarboxylase process, with the hope to facilitate the industrial production of L-HPA.
Amino Acids ; Environmental Pollution ; Industry ; Protein Biosynthesis

Alpha-keto acid is a bifunctional organic compound containing both carboxyl and ketone groups, and widely applied in the industries of food, pharmaceutical and cosmetics. Based on the demand of eco-friendly process, safety and sustainable development, production of α-keto acids by enzymatic conversion technology has been paid more and more attention. In this article, we review the status of α-keto acids biosynthesis from three aspects: enzymatic screening, enzymatic modification and optimization of enzymatic conversion conditions. Meanwhile, we also indicate future research directions for further improving α-keto acids production.
Keto Acids ; metabolism

As an essential amino acid, l-tryptophan is widely used in food, feed and medicine sectors. Nowadays, microbial l-tryptophan production suffers from low productivity and yield. Here we construct a chassis E. coli TRP3 producing 11.80 g/L l-tryptophan, which was generated by knocking out the l-tryptophan operon repressor protein (trpR) and the l-tryptophan attenuator (trpL), and introducing the feedback-resistant mutant aroG^fbr. On this basis, the l-tryptophan biosynthesis pathway was divided into three modules, including the central metabolic pathway module, the shikimic acid pathway to chorismate module and the chorismate to tryptophan module. Then we used promoter engineering approach to balance the three modules and obtained an engineered E. coli TRP9. After fed-batch cultures in a 5 L fermentor, tryptophan titer reached to 36.08 g/L, with a yield of 18.55%, which reached 81.7% of the maximum theoretical yield. The tryptophan producing strain with high yield laid a good foundation for large-scale production of tryptophan.
Escherichia coli/metabolism* ; Tryptophan ; Metabolic Engineering ; Bioreactors ; Metabolic Networks and Pathways

Konjac glucomannan (KGM) is a water-soluble polysaccharide obtained from the roots and tubers of konjac plants. Recently, a degraded product of KGM, depolymerized KGM (DKGM), has attracted attention because of its low viscosity, improved hydrophily, and favorable physiological functions. In this review, we describe the preparation of DKGM and its prebiotic effects. Other health benefits of DKGM, covering antioxidant and immune activity, are also discussed, as well as its safety. DKGM could be a candidate for use as a tool for the treatment of various diseases, including intestinal flora imbalance, and oxidative- and immune-related disorders.
Amorphophallus ; chemistry ; Animals ; Antioxidants ; isolation & purification ; therapeutic use ; Humans ; Hydrophobic and Hydrophilic Interactions ; Immunologic Factors ; isolation & purification ; therapeutic use ; Mannans ; isolation & purification ; therapeutic use ; Plants, Medicinal ; chemistry ; Polymerization ; Prebiotics ; Safety ; Viscosity