Glycosylation is one of the most important reactions in living organisms as it results in the formation of glycoconjugates with diverse biological functions. Sugar nucleotides are structurally composed of sugar and nucleoside diphosphate or monophosphate, which are widespread within a variety of biological cells. As glycosyl donors for the transglycosyl reactions catalyzed by Leloir-type glycosyltransferases, sugar nucleotides are essential for the synthesis of glycans and glycoconjugates. However, high costs and limited availability of nucleotide sugars prevent applications of biocatalytic cascades on an industrial scale. Therefore, attentions on synthetic strategies of sugar nucleotides have been increasing to achieve their wide applications in various fields. The 9 common sugar nucleotides in mammals have been fully studied with large-scale synthesis through chemical, enzymatic (chemo-enzymatic) and cell factory strategies. In addition to common sugar nucleotides, many rare sugar nucleotides are present in plants and bacteria. Although unnatural sugar nucleotides cannot be synthesized in organisms, they have great potential in research as substrates for glycosyltransferases in carbohydrate synthesis, as enzyme inhibitors in biochemical studies, and as components of glycoconjugate biosynthesis. Therefore, increasing attention has been paid to explore the efficient synthesis of unnatural sugar nucleotides. Currently, strategies for chemical synthesis of sugar nucleotides have been greatly improved, such as the use of effective catalysts for forming pyrophosphate bonds and the development of entirely new synthesis protocols. Multiple sugar nucleotides, especially unnatural sugar nucleotides, are synthesized chemically. However, chemical synthesis requires tedious protection and deprotection steps, resulting in complex steps, high cost and low yield. In contrast, enzymatic (chemo-enzymatic) and cell factory methods have significant advantages such as high yield, easy operation and easy process scale-up in the preparation of sugar nucleotides. Hence, they are prominent strategies for sugar nucleotide preparation. Herein, the biosynthesis and application of sugar nucleotides are reviewed, mainly focusing on the 9 sugar nucleotides common in mammals. The early strategies for enzymatic synthesis of sugar nucleotides generally used de novo synthesis pathway. With the discoveries of enzymes involved in salvage pathway of sugar nucleotide synthesis and the development of one-pot multienzyme (OPME) method, the synthesis of sugar nucleotides was greatly simplified. Cell factory method employs the microbial living cells as a “processing plant” by engineering their metabolic pathways through genetic engineering technology. The cell factory method has high yield, and has been applied for efficient synthesis of several sugar nucleotides. Moreover, the strategy of gram-scale synthesis of multiple rare sugar nucleotides by cascade reactions from common sugar nucleotides using sugar nucleotides synthases cloned from different sources was illustrated. In recent years, the synthesis cost of sugar nucleotides has been further reduced through various ways, such as regeneration of nucleotides, regeneration of organic cofactors, and application of immobilized enzyme technology. Furthermore, through the continuous improvement of sugar nucleotide purification process, the use of high concentration of multi-enzyme cascade and rapid non-chromatographic purification process, the synthesis of multiple sugar nucleotides and their derivatives from monosaccharides was achieved, which gradually broke the limitations of the existing strategy. With the efficient synthesis of sugar nucleotides, their applications in various fields have been increasingly explored, including the synthesis of glycans and glycoconjugates, biochemical characterization of glycosyltransferases and bioorthogonal labeling strategies, which are of great significance to the research of biochemistry, glycobiology and the development of related pharmaceutical products.

ObjectiveThe detection of RNA single nucleotide polymorphism (SNP) is of great importance due to their association with protein expression related to various diseases and drug responses. At present, splintR ligase-assisted methods are important approaches for RNA direct detection, but its specificity will be limited when the fidelity of ligases is not ideal. The aim of this study was to create a method to improve the specificity of splintR ligase for RNA detection. MethodsIn this study, a dual-competitive-padlock-probe (DCPLP) assay without the need for additional enzymes or reactions is proposed to improve specificity of splintR ligase ligation. To verify the method, we employed dual competitive padlock probe-mediated rolling circle amplification (DCPLP-RCA) to genotype the CYP2C9 gene. ResultsThe specificity was well improved through the competition and strand displacement of dual padlock probe, with an 83.26% reduction in nonspecific signal. By detecting synthetic RNA samples, the method demonstrated a dynamic detection range of 10 pmol/L-1 nmol/L. Furthermore, clinical samples were applied to the method to evaluate its performance, and the genotyping results were consistent with those obtained using the qPCR method. ConclusionThis study has successfully established a highly specific direct RNA SNP detection method, and provided a novel avenue for accurate identification of various types of RNAs.

Programmed cell death 1 ligand 1 (PD-L1) is an important immunosuppressive molecule, which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1. The PD-L1 expression disorder plays an important role in the occurrence, development, and treatment of sepsis or other inflammatory diseases, and has become an important target for the treatment of these diseases. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with multiple differentiation potential. In recent years, MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases. Moreover, PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases. In this review, we will summarize the main regulatory mechanism of PD-L1 expression, and discuss various biological functions of PD-L1 in the immune regulation of MSCs.

The methanol extract of Huperzia serrata was separated and purified by ODS, AB-8 macroporous adsorption resin, dextran gel Sephadex LH-20 and silica gel column chromatography combined with the semi-pre HPLC. The chemical structures of the isolated compounds were identified by MS, IR, NMR, etc. Four compounds were isolated from Huperzia serrata and identified, named as serratinine C (1), lycobeline C (2), diphaladin A (3) and crenatine (4). Compound 1 is a new alkaloid, compounds 2-4 were isolated for the first time. In vitro biological activity experiments showed that compound 1 could significantly reduce the levels of nitric oxide and reactive oxygen species in glial cells induced by lipopolysaccharide and had significant antioxidant biological activity.

Objective To investigate the clinical features and prognosis of childhood acute lymphoblastic leukemia (ALL) with CREBBP gene mutation. Methods A retrospective analysis was performed for the clinical data of 14 ALL children with CREBBP gene mutation who were admitted to Children's Hospital of the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2023. Results The ALL patients with CREBBP gene mutation accounted for 1.5％ (14/963) among all children diagnosed with ALL during the same period of time,among whom there were 4 boys (29％) and 10 girls (71％),with a median age of 4 years and 3.5 months. All children had an immunological type of B-cell ALL and concurrent mutations in other genes including NRAS,KRAS,ETV6,FLT3,PAX5,SH2B3,CDKN2A,and CDKN2B,and 4 children had karyotype abnormality. All 14 children received induction therapy with the VDLP regimen,with a complete remission (CR) rate of 79％ (11/14) after the first course of treatment. Three children experienced bone marrow recurrence alone,with a recurrence rate of 21％ (3/14),among whom 1 child achieved CR after blinatumomab therapy and 2 received bridging hematopoietic stem cell transplantation after chemotherapy for recurrence. Among the 14 children,1 died due to treatment discontinuation and 13 achieved disease-free survival. The 5-year overall survival rate was 92％±7％,and the event-free survival rate was 73％±13％. Conclusions ALL with CREBBP gene mutation is more common in girls and has a low induction remission rate and a high recurrence rate,and it is often accompanied by other types of gene mutations and abnormal karyotypes. Most children with recurrence can achieve long-term survival after immunotherapy or hematopoietic stem cell transplantation.

Objective To study the mechanism of polyene phosphatidylcholine in improving metabolic disorders and fatty liver induced by high fat diet.Methods Thirty-two C57BL/6 mice were randomly divided into blank group,control group,model group and experimental group.The blank group was fed with low-fat diet and intraperitoneal injection of 10％glucose 200 μL twice a week.Control group was fed with low-fat diet twice a week and intraperitoneally injected 10％glucose solution 200 μL containing polyene phosphatidylcholine(PPC)20 μg.Model group was fed with high-fat diet and intraperitoneal injection of 10％glucose 200 μL twice a week.Experimental group was fed with high-fat diet twice a week and intraperitoneally injected 10％glucose solution 200 μL containing PPC 20 μg.The body weight of the mice was measured,blood glucose test strips and insulin resistance was analyzed.The levels of triglyceride(TG),high density lipoprotein(HDL),low density lipoprotein(LDL),glutamic oxalic aminotransferase(GOT)and glutamic pyruvic aminotransferase(GPT)in serum and liver were analyzed by biochemical method.The levels of tumor necrosis factor-α(TNF-α),interleukin-6 and IL-8 were detected by enzyme-linked immunosorbent assay(ELISA).Results The serum TG levels of blank group,control group,model group and experimental group were(0.15±0.01),(0.11±0.01),(0.21±0.01)and(0.12±0.01)mmol·L-1;LDL levels were(0.41±0.01),(0.25±0.01),(0.71±0.02)and(0.49±0.01)mmol·L-1;GOT levels were(30.30±0.89),(31.39±1.18),(43.04±2.82)and(25.64±0.72)mmol·L-1;GPT levels were(9.15±0.45),(7.39±1.88),(12.87±1.81)and(7.96±1.64)mmol·L-1;fasting blood glucose levels were(4.97±0.08),(6.08±0.18),(8.12±0.20)and(7.29±0.02)mmol·L-1;fasting insulin levels were(6.52±1.11),(5.45±0.28),(54.83±4.32)and(30.55±2.73)mU·L-1;the levels of TNF-α in liver tissues were(3.98±0.63),(3.95±0.98),(20.55±4.71)and(15.28±1.73)pg·g-1;IL-6 levels were(18.93±8.56),(17.64±3.29),(59.40±4.63)and(37.54±7.33)pg·g-1;IL-8 levels were(67.16±12.37),(59.44±3.58),(198.40±9.27)and(132.10±7.04)pg·g-1.The difference of above indicatory between experimental group and model group was statistically significant(all P＜0.05).Conclusion Polyene phosphatidylcholine may inhibit the expression of TNF-α,IL-6 and IL-8 inflammatory factors by mediating the inhibition of inflammation on liver tissue and then improve metabolic disorders.

The current research status of different structures,driving modes and training modes of hand rehabilitation robots at home and abroad was introduced.The disadvantages of the existing hand rehabilitation robots were analyzed.It's pointed out hand rehabilitation robots in the future would involve in the combination of rigid and flexible wearing,new intelligent driving mode and multi-mode rehabilitation training.[Chinese Medical Equipment Journal,2024,45(11):88-96]

A large number of studies have demonstrated that mRNA vaccine has been characterized as a technique with good safety, strong immunogenicity and high developmental potential, which makes it have broad prospects in immunotherapy. In recent years, the stability and in vivo delivery efficiency of mRNA vaccines have been largely addressed by the progresses in mRNA engineering and delivery innovation. And some mRNA vaccines are now clinical approved or in preclinical trials. Here, we summarize current knowledge on the research advances, technology, and application in major infectious diseases in humans and animals of mRNA vaccines, with the aim to provide a reference for improving the development of novel mRNA vaccines.
Animals ; Humans ; Communicable Diseases ; Vaccines, Synthetic/genetics* ; mRNA Vaccines

Child ; Humans ; Liver Diseases ; Terminology as Topic

OBJECTIVE: To investigate the short-term clinical effect of lumbar nerve root canal injection under X-ray angiography in the treatment of sciatica. METHODS: The clincal data of 78 patients with sciatica underwent lumbar nerve root canal injection under X-ray angiography from December 2017 to February 2020 was retrospectively analyzed. Including 31 males and 47 females, aged from 22 to 88 years old with a median of 65 years. There were 55 cases of lumbar disc herniation and 23 cases of lumbar spinal stenosis, the course of disease ranged from 1 to 8 weeks with a median of 3 weeks. There were 71 cases of single segment disc herniation or stenosis, including L_3,4 of 5 cases, L_4,5 of 61 cases, L₅S₁ of 5 cases, and 7 cases of multisegment herniation or stenosis. The pain visual analogue scale (VAS) was recorded and Macnab was used to evaluate the clinical effect. RESULTS: All patients completed standardized treatment without serious adverse reactions. VAS were (3.21±0.76) scores immediately after treatment, (2.89±0.33) scores 1 hour after treatment, (1.80±0.27) scores 6 hours after treatment, (1.10±0.20) scores 24 hours after treatment, (2.53±0.35) scores 1 week after treatment and (4.27±0.36) scores 1 month after treatment. There were significant differences in VAS between before treatment(7.83±0.56) and each time period after treatment(P<0.05). According to Macnab low back pain evaluation standard, 42 cases were effective, 34 cases were markedly effective and 2 cases were ineffective within 24 hours after treatment, with an effective rate of 97.4%;38 cases were effective, 25 cases were markedly effective, 15 cases were ineffective within one week after treatment, the effective rate was 80.0%;32 cases were effective, 22 cases were markedly effective, 24 cases were ineffective within one month after treatment, the effective rate was 69.2%. CONCLUSION The short-term clinical effect of nerve root canal injection under X-ray radiography in the treatment of sciatica is good and it is an effective method to relieve sciatica.
Adult ; Aged ; Aged, 80 and over ; Angiography ; Dental Pulp Cavity ; Female ; Humans ; Intervertebral Disc Displacement/diagnostic imaging* ; Lumbar Vertebrae/diagnostic imaging* ; Male ; Middle Aged ; Retrospective Studies ; Sciatica/drug therapy* ; Treatment Outcome ; X-Rays ; Young Adult