Effect of pinoresinol-lariciresinol reductases on biosynthesis of lignans with substrate selectivity in Schisandra chinensis

Schisandra lignans are the main bioactive compounds found in Schisandra chinensis fruits, such as schisandrol lignans and schisandrin lignans, which play important roles in organ protection or other clinical roles. Pinoresinol-lariciresinol reductase (PLR) plays a pivotal role in plant lignan biosynthesis, however, limited research has been conducted on S. chinensis PLR to date. This study identified five genes as ScPLR, successfully cloned their coding sequences, and elucidated their catalytic capabilities. ScPLR3-5 could recognize both pinoresinol and lariciresinol as substrates, and convert them into lariciresinol and secoisolariciresinol, respectively, while ScPLR2 exclusively catalyzed the conversion of (+)-pinoresinol into (+)-lariciresinol. Transcript-metabolite correlation analysis indicated that ScPLR2 exhibited unique properties that differed from the other members. Molecular docking and site-directed mutagenesis revealed that Phe271 and Leu40 in the substrate binding motif were crucial for the catalytic activity of ScPLR2. This study serves as a foundation for understanding the essential enzymes involved in schisandra lignan biosynthesis.

Identification and Expression Analysis of R2R3-MYB Transcription Factors Associated with Flavonoid Biosynthesis in Panax quinquefolius

Panax quinquefolius L. is an important medicinal plant, and flavonoids are among its main secondary metabolites. The R2R3-MYB transcription factor plays an irreplaceable role in plant growth, development, and secondary metabolism. In our study, we identified 159 R2R3-MYBs and analyzed their physical and chemical properties in P. quinquefolius. The protein length of 159 PqMYBs varied from 107 to 1050 amino acids. The molecular weight ranged from 12.21 to 116.44 kDa. The isoelectric point was between 4.57 and 10.34. We constructed a phylogenetic tree of P. quinquefolius and Arabidopsis thaliana R2R3-MYB family members, and PqMYB members were divided into 33 subgroups. Transcriptome data analysis showed that the expression patterns of PqMYBs in root, leaf, and flower were significantly different. Following the MeJA treatment of seedlings, five candidate PqMYB genes demonstrated a response. A correlation analysis of PqMYBs and candidate flavonoid pathway genes showed that PqMYB2, PqMYB46, and PqMYB72 had correlation coefficients that were higher than 0.8 with PqCHS, PqANS4, and PqCCoAMT10, respectively. Furthermore, a transient expression assay confirmed that the three PqMYBs were localized in the nucleus. We speculated that these three PqMYBs were related to flavonoid biosynthesis in P. quinquefolius. These results provided a theoretical basis and a new perspective for further understanding the R2R3-MYB gene family and the biosynthesis mechanism of secondary metabolites in P. quinquefolius.

Identification and analysis of BAHD superfamily related to malonyl ginsenoside biosynthesis in Panax ginseng

Introduction

The BAHD (benzylalcohol O-acetyl transferase, anthocyanin O-hydroxycinnamoyl transferase, N-hydroxycinnamoyl anthranilate benzoyl transferase and deacetylvindoline 4-O-acetyltransferase), has various biological functions in plants, including catalyzing the biosynthesis of terpenes, phenolics and esters, participating in plant stress response, affecting cell stability, and regulating fruit quality.

Methods

Bioinformatics methods, real-time fluorescence quantitative PCR technology, and ultra-high-performance liquid chromatography combined with an Orbitrap mass spectrometer were used to explore the relationship between the BAHD gene family and malonyl ginsenosides in Panax ginseng.

Results

In this study, 103 BAHD genes were identified in P. ginseng, mainly distributed in three major clades. Most PgBAHDs contain cis-acting elements associated with abiotic stress response and plant hormone response. Among the 103 genes, 68 PgBAHDs are WGD (whole-genome duplication) genes. The significance of malonylation in biosynthesis has garnered considerable attention in the study of malonyltransferases. The phylogenetic tree results showed 34 PgBAHDs were clustered with genes that have malonyl characterization. Among them, seven PgBAHDs (PgBAHD4, 45, 65, 74, 90, 97, and 99) showed correlations > 0.9 with crucial enzyme genes involved in ginsenoside biosynthesis and > 0.8 with malonyl ginsenosides. These seven genes were considered potential candidates involved in the biosynthesis of malonyl ginsenosides.

Discussion

These results help elucidate the structure, evolution, and functions of the P. ginseng BAHD gene family, and establish the foundation for further research on the mechanism of BAHD genes in ginsenoside biosynthesis.

[A follow-up study of the severe occlusal surface wear of implant-supported full-arch prostheses]

Objective: To evaluate the severe occlusal surface wear of implant-supported full-arch prostheses, and to explore the risk factors affecting the severe occlusal surface wear of implant-supported full-arch prostheses. Methods: Five hundred and thirty-five patients who received implant-supported fixed complete dental prostheses or implant-overdentures and completed at least one follow-up 3 months after the delivery of definitive prostheses were enrolled from October 1994 to October 2021 in this retrospective cohort study. The information on demographics, implants, definitive prostheses, and related outcomes was collected. Cox proportional hazard regression model was adopted to analyze the risk factors of the severe wear of occlusal surfaces in implant-supported full-arch prostheses. Univariate analysis was performed on the factors that may affect the severe wear of occlusal surfaces, and the parameters of P<0.10 in univariate analysis were included in multivariate analysis to explore the risk factors affecting the severe wear of occlusal surfaces in implant-supported full-arch prostheses. Results: Severe wear of the posterior occlusal surfaces was detected in 114 prostheses with a duration of 61.4 (33.3, 89.4) months. 13 cases occurred≤2 years after the delivery of definitive prostheses, 44 cases>2 years and≤5 years, 44 cases>5 years and≤10 years, and the other 13 cases>10 years. There was no significant difference in the average time of severe occlusal surface wear between implant-supported fixed complete dental prostheses and implant-overdentures in the maxilla (Z=-1.03, P=0.303). However, in the mandible, it was 48.2 (31.2, 80.2) and 79.2 (51.3, 119.1) months respectively, which was statistically significant (Z=-2.93, P=0.003). Cox proportional hazard regression model showed opposed fixed dentition, bruxism, and posterior resin occlusal surfaces were risk factors (P<0.05) affecting the severe wear of the occlusal surfaces. Conclusions: Severe occlusal surface wear was clinically common with the prolonged application of implant-supported full-arch prostheses. Prostheses opposed to fixed dentition, in patients with bruxism, and made of posterior resin materials were at higher risk of severe occlusal surface wear on the posterior artificial teeth. Regular follow-up, patients' behavior guidance, and clinicians' appropriate intervention were necessary to manage this complication.

Single-stage computer-assisted approach for tumour resection and functional restoration of Brown class III maxillary defects-titanium mesh and zygomatic implants combined with vascularized anterolateral thigh flap

The functional restoration of Brown class III maxillary defects is a challenging endeavour in oral and maxillofacial surgery. Conventional reconstruction techniques with osseous free flaps have certain limitations, such as the need for multiple operations and greater patient morbidity. This study introduces a single-stage computer-assisted approach for tumour resection and functional restoration of these defects using titanium mesh, zygomatic implants, and a vascularized anterolateral thigh flap (ALTF). Virtual surgical planning was used to simulate tumour resection, titanium mesh placement, and zygomatic implant insertion. Surgery was performed under the guidance of mixed reality and surgical navigation. The tumour was resected by total hemimaxillectomy, and the reconstruction was performed using a pre-bent patient-specific titanium mesh for the orbital floor and two zygomatic implants placed and exposed through tunnels in an ALTF. The ALTF survived without any perioperative complications. A fixed prosthesis with built-in titanium frame was delivered 4 months postoperatively. At the 1-year follow-up, there was no tumour recurrence, the implants were osseointegrated, and aesthetics and masticatory function were satisfactory. An occlusal force of 155 N was attained on the reconstructed side, compared to 127 N on the non-surgical side.

Phenotyping of Salvia miltiorrhiza Roots Reveals Associations between Root Traits and Bioactive Components

Plant phenomics aims to perform high-throughput, rapid, and accurate measurement of plant traits, facilitating the identification of desirable traits and optimal genotypes for crop breeding. Salvia miltiorrhiza (Danshen) roots possess remarkable therapeutic effect on cardiovascular diseases, with huge market demands. Although great advances have been made in metabolic studies of the bioactive metabolites, investigation for S. miltiorrhiza roots on other physiological aspects is poor. Here, we developed a framework that utilizes image feature extraction software for in-depth phenotyping of S. miltiorrhiza roots. By employing multiple software programs, S. miltiorrhiza roots were described from 3 aspects: agronomic traits, anatomy traits, and root system architecture. Through K-means clustering based on the diameter ranges of each root branch, all roots were categorized into 3 groups, with primary root-associated key traits. As a proof of concept, we examined the phenotypic components in a series of randomly collected S. miltiorrhiza roots, demonstrating that the total surface of root was the best parameter for the biomass prediction with high linear regression correlation (R2 = 0.8312), which was sufficient for subsequently estimating the production of bioactive metabolites without content determination. This study provides an important approach for further grading of medicinal materials and breeding practices.

Functional divergence of CYP76AKs shapes the chemodiversity of abietane-type diterpenoids in genus Salvia

The genus Salvia L. (Lamiaceae) comprises myriad distinct medicinal herbs, with terpenoids as one of their major active chemical groups. Abietane-type diterpenoids (ATDs), such as tanshinones and carnosic acids, are specific to Salvia and exhibit taxonomic chemical diversity among lineages. To elucidate how ATD chemical diversity evolved, we carried out large-scale metabolic and phylogenetic analyses of 71 Salvia species, combined with enzyme function, ancestral sequence and chemical trait reconstruction, and comparative genomics experiments. This integrated approach showed that the lineage-wide ATD diversities in Salvia were induced by differences in the oxidation of the terpenoid skeleton at C-20, which was caused by the functional divergence of the cytochrome P450 subfamily CYP76AK. These findings present a unique pattern of chemical diversity in plants that was shaped by the loss of enzyme activity and associated catalytic pathways.

Whole-genome identification and expression profiling of growth-regulating factor (GRF) and GRF-interacting factor (GIF) gene families in Panax ginseng

BACKGROUND

Panax ginseng is a perennial herb and one of the most widely used traditional medicines in China. During its long growth period, it is affected by various environmental factors. Past studies have shown that growth-regulating factors (GRFs) and GRF-interacting factors (GIFs) are involved in regulating plant growth and development, responding to environmental stress, and responding to the induction of exogenous hormones. However, GRF and GIF transcription factors in ginseng have not been reported.

RESULTS

In this study, 20 GRF gene members of ginseng were systematically identified and found to be distributed on 13 chromosomes. The ginseng GIF gene family has only ten members, which are distributed on ten chromosomes. Phylogenetic analysis divided these PgGRFs into six clades and PgGIFs into two clades. In total, 18 of the 20 PgGRFs and eight of the ten PgGIFs are segmental duplications. Most PgGRF and PgGIF gene promoters contain some hormone- and stress- related cis-regulatory elements. Based on the available public RNA-Seq data, the expression patterns of PgGRF and PgGIF genes were analysed from 14 different tissues. The responses of the PgGRF gene to different hormones (6-BA, ABA, GA3, IAA) and abiotic stresses (cold, heat, drought, and salt) were studied. The expression of the PgGRF gene was significantly upregulated under GA3 induction and three weeks of heat treatment. The expression level of the PgGIF gene changed only slightly after one week of heat treatment.

CONCLUSIONS

The results of this study may be helpful for further study of the function of PgGRF and PgGIF genes and lay a foundation for further study of their role in the growth and development of Panax ginseng.

Deciphering the transcriptomic response of Ilyonectria robusta in relation to ginsenoside Rg1 treatment and the development of Ginseng rusty root rot

Rusty root rot is a severe disease in Ginseng (Panax ginseng C.A.Mey.) production caused by Ilyonectria robusta. The severity of the disease may be related to the residual ginsenosides in soil. In order to elucidate the response mechanism between Rg1 treatment and occurrence of ginseng rust, we performed growth, reproduction and transcriptome analysis on Rg1-treated. The results showed that Rg1 significantly promoted the mycelial growth, and sporulation compared to the control, and aggravated the disease symptoms of Panax ginseng. A total of 6708 transcripts out of 213 131 annotated genes identified from global transcriptomic analysis were differentially expressed in Ilyonectria robusta grown in the Rg1 treatment. These genes were found to be related to the carbon-nitrogen metabolism, transport, and assimilation. Many of these genes were also associated with pathogenicity based on the Phi-base database. Several transcription factors were related to specific biological processes, such as nitrogen utilization. The current results revealed that Rg1 played a major role in the development of rusty root rot by promoting fungal cell growth and affected the expression of genes required for pathogenesis. Rg1 could aggravate the invasion of Ilyonectria robusta on ginseng root, which preliminarily revealed the reason for the aggravation of rusty root rot in ginseng soil-borne.

Alternative Splicing Dynamics During the Lifecycle of Salvia miltiorrhiza Root Revealed the Fine Tuning in Root Development and Ingredients Biosynthesis

Alternative splicing (AS) is an essential post-transcriptional process that enhances the coding and regulatory potential of the genome, thereby strongly influencing multiple plant physiology processes, such as metabolic biosynthesis. To explore how AS affects the root development and synthesis of tanshinones and phenolic acid pathways in Salvia miltiorrhiza roots, we investigated the dynamic landscape of AS events in S. miltiorrhiza roots during an annual life history. Temporal profiling represented a distinct temporal variation of AS during the entire development stages, showing the most abundant AS events at the early seedling stage (ES stage) and troughs in 45 days after germination (DAG) and 120 DAG. Gene ontology (GO) analysis indicated that physiological and molecular events, such as lateral root formation, gravity response, RNA splicing regulation, and mitogen-activated protein kinase (MAPK) cascade, were greatly affected by AS at the ES stage. AS events were identified in the tanshinones and phenolic acids pathways as well, especially for the genes for the branch points of the pathways as SmRAS and SmKSL1. Fifteen Ser/Arg-rich (SR) proteins and eight phosphokinases (PKs) were identified with high transcription levels at the ES stage, showing their regulatory roles for the high frequency of AS in this stage. Simultaneously, a co-expression network that includes 521 highly expressed AS genes, SRs, and PKs, provides deeper insight into the mechanism for the variable programming of AS.

[Immediate rehabilitation of edentulous mandibles with implant-supported full-arch prostheses by intra-oral welding technique: a two-year follow-up]

Objective: To evaluate the 2-year clinical outcome of immediate loading implant-supported fixed full-arch prostheses in mandibles using intra-oral welding technique and to discuss the characteristics of the technique. Methods: Totally 15 patients (4 males and 11 females) who treated with immediate rehabilitation of edentulous mandibles with implant-supported full-arch prostheses from July 2015 to February 2019 in Department of Implantology, Peking University School and Hospital of Stomatology were included in the present study. The patients' average age was 64.2±9.3 years. In each case, 4 implants were placed in the mandible area, a titanium bar was connected with each of the implants by using intra-oral welding technique as the Ti-metal framework of the prostheses. Pre-fabricated abutment-level fixed prostheses were delivered immediately after the surgery. A total of 60 implants, 15 mandibles were treated. Biological and mechanical complications, hygiene of the tissue-contacted surface of the restoration and patients' satisfactory grade were recorded. The radiological fitness of welded frameworks to abutments, survival rate of implants and marginal bone loss were calculated and analyzed. The observation period of the study was 24-55 months, with an average of 34.9 months. Results: All of the 15 cases of welded bar-abutment frameworks were fixed on implants with well passive fitness in clinical and radiological level. However, 2 of the 60 implants were failed by loss of osseointegration, and the result of implant survival rate of 96.7% in 2 years. The average marginal bone loss was (0.7±0.2) mm. The average bleeding index of the 58 implants remained was under 3 without clinical signs of gingival swelling, tenderness or fistula. No mechanical complications, such as break or distortion of the implants, occurred. Fracture of artificial teeth and complex resin area happened in 6 of the 15 prostheses. The average debris index was 3.4±0.4 and the hygiene of the tissue-contact areas was under satisfactory condition. Conclusions: Using the intra-oral welding technique to achieve a rigid splint of implants, the clinical outcome of the newly performed technique was predictable in early stage. The frame structure remained stable to avoiding the occurrence of mechanical complications. The provisional restoration could be expected to provide long functional period. Long term result of the treatment were needed for further observation.

Genome-wide characterization and analysis of WRKY transcription factors in Panax ginseng

BACKGROUND

Panax ginseng is a well-known medicinal plant worldwide. As an herbal medicine, ginseng is also known for its long lifecycle, which can reach several decades. WRKY proteins play regulatory roles in many aspects of biological processes in plants, such as responses to biotic or abiotic stress, plant development, and adaptation to environmental challenges. Genome-wide analyses of WRKY genes in P. ginseng have not been reported.

RESULTS

In this study, 137 PgWRKY genes were identified from the ginseng genome. Phylogenetic analysis showed that the PgWRKYs could be clustered into three primary groups and five subgroups. Most of the PgWRKY gene promoters contained several kinds of hormone- and stress-related cis-regulatory elements. The expression patterns of PgWRKY genes in 14 different tissues were analyzed based on the available public RNA-seq data. The responses of the PgWRKY genes to heat, cold, salt and drought treatment were also investigated. Most of the PgWRKY genes were expressed differently after heat treatment, and expression trends changed significantly under drought and cold treatment but only slightly under salt treatment. The coexpression analysis of PgWRKY genes with the ginsenoside biosynthesis pathway genes identified 11 PgWRKYs that may have a potential regulatory role in the biosynthesis process of ginsenoside.

CONCLUSIONS

This work provides insights into the evolution, modulation and distribution of the WRKY gene family in ginseng and extends our knowledge of the molecular basis along with modulatory mechanisms of WRKY transcription factors in ginsenoside biosynthesis.

[Plaque accumulation at the fitting surface and cleaning status in patients with full-arch implant-supported fixed prostheses: a cross sectional study]

Objective: To observe the plaque accumulation at the fitting surface and oral hygiene status in patients with full-arch implant-supported fixed prostheses, and explore the possible influencing factors. Methods: Twenty-eight patients [17 males and 11 females, (63.0± 10.8) years old] with 40 full-arch implant-supported fixed prostheses (18 maxillary and 22 mandibular) were collected from January 2012 to September 2020 in Department of Implantology, Peking University School and Hospital of Stomatology. Plaque accumulation at the fitting surfaces were evaluated during the follow-up visit after 6 months following definitive prostheses delivery, by analyzing the digital photographs recorded by ImageJ. Meanwhile, the cleanliness of the fitting surface of prostheses and oral hygiene status were recorded. The oral hygiene habits and the patients' satisfaction with the prostheses were investigated by questionnaire, and the difference of plaque accumulation between different cleaning habits of dentures were compared. Results: The debris index of the fitting surface of the 40 full-arch implant-supported fixed prostheses were 3.28±0.75, and the percentage of area covered with plaque was (51.6±19.0)%. The debris index and plaque accumulation of the mandibular prostheses were significantly higher than that of the maxillary prostheses (P<0.05). In most mandibular prostheses (16/22), calculus was attached to the lingual side of the anterior tooth area. The reserved cleaning space of the restoration showed more plaque accumulation than in other parts. There was no significant difference in the percentage of area covered with plaque between groups with different cleaning habits. The satisfaction survey results indicated the "clean" project had a lowest score. Conclusions: The cleanliness of patients with full-arch implant-supported fixed prostheses was poor, and the hygiene status of the mandibular prostheses was worse than that of maxillary, especially in the anterior tooth area of mandibular prostheses. The influence of different cleaning habits on plaque accumulation was not observed.

OPTIMIZING THE REGULATION AND CONTROL OF SPORTS INJURY AND FATIGUE OF WINTER OLYMPIC ICE AND SNOW ATHLETES BASED ON INJURY PREVENTION

ABSTRACT This study reveals the characteristics and relationship of sports injury and fatigue of the Winter Olympics athletes, and monitors the athletes’ psychological condition through case analysis of excellent athletes, and provides empirical evidence for athletes’ psychological training and preparation for the physical and mental health services of Winter Olympics. Through questionnaires, literature review and other methods to study the injury situation of Winter Olympics ice and snow athletes, the results show that the proportion of chronic lumbar and knee joint injuries, and repeated muscle strains of Chinese Winter Olympics ice and snow athletes is large, and the cure rate is not high. The preparation activities are neither paid enough attention or sufficient, and the rationality of training plan arrangement is insufficient. The main cause of injury is insufficient understanding of the mechanism of injury and illness among athletes and coaches. Individual elite athletes need to improve their coping skills and pay attention to their psychological fatigue. In view of the sports’ psychological characteristics and the problems faced by winter athletes, personalized psychological intervention programs should be formulated.

The p53/p21/p16 and PI3K/Akt signaling pathways are involved in the ameliorative effects of maltol on D-galactose-induced liver and kidney aging and injury

Successive evidence has established that maltol, a flavor-enhancing agent, could provide resistance to oxidative stress-induced tissue injury in various animal models though its benefits for aging-induced liver and kidney injuries are still undetermined. In the present work, for demonstrating maltol's ameliorative effect and probable mechanism against aging-induced liver and kidney injuries, D-galactose (D-Gal)-induced animal in vivo and HEK293 cells in vitro models were established and results demonstrated that long-term D-Gal treatment increases the accumulation of advanced glycation end products (AGEs) in liver and kidney tissues, mitigates cell viability, and arrests the cycle. Interestingly, 4-weeks maltol treatment at 50 and 100 mg/kg activated aging-associated proteins including p53, p21, and p16 followed by inhibiting malondialdehyde (MDA)'s over-production and increasing the levels of antioxidant enzymes. Therefore, decreases in cytochrome P450 E1 (CYP2E1) and 4-hydroxydecene (4-HNE)'s immunofluorescence expression levels are confirmed. Furthermore, maltol improved oxidative stress injury by activating the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. In conclusion, the purpose of the present study was to estimate the mechanistic insights into maltol's role as an antioxidant in liver and kidney cell senescence and injury, which will reflect potential of therapeutic strategy for antiaging and aging-related disease treatment.

Pulchinenoside B4 exerts the protective effects against cisplatin-induced nephrotoxicity through NF-κB and MAPK mediated apoptosis signaling pathways in mice

Cisplatin (cis-Dichlorodiammine platinum, CP), as the first-line chemotherapy drug of choice for many cancers such as urogenital system tumors and digestive tract tumors, also causes toxicity and side effects to the kidney. Previous studies have shown that Pulsatilla chinensis has significant anti-inflammatory and antioxidant activities, but the mechanism of cisplatin induced acute kidney injury (AKI) in vivo has not been thoroughly studied. The purpose of this study is to investigate the protective effect of pulchinenoside B4 (PB4), a representative and major component with a content of up to 10% in root of P. chinensis, on AKI induced by CP in mice. Our results indicated the significant protective effect of PB4 by evaluating renal function indicators, inflammatory factor levels and renal histopathological changes. In addition, PB4 may mainly act on NF-κB signaling pathway to reduce the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in the kidney after CP exposure, thus exerting anti-inflammatory activity. Furthermore, PB4 regulated MAPK signaling pathway and its downstream apoptotic factors to inhibit the occurrence of apoptosis, such as Bax, Bcl-2, caspase 3 and caspase 9. Notably, the activations of caspase 3 induced by cisplatin were strikingly reduced in PB4-treated mice. Therefore, the above evidence suggested that PB4 is a potential renal protectant with significant anti-inflammatory and anti-apoptotic effects.

[Immediate rehabilitation of the edentulous and potential edentulous jaws with implant-supported full-arch prostheses: a retrospective analysis of 225 cases]

Objective: To evaluate the outcomes of immediate rehabilitation of the edentulous and potential edentulous jaws with implant-supported full-arch prostheses and analyse the risk factors of the complications. Methods: This retrospective study included 273 patients treated with immediate rehabilitation of the edentulous and potential edentulous jaws with implant-supported full-arch prostheses from April 2008 to December 2018 in Department of Implantology, Peking University School and Hospital of Stomatology. The patients' sex, age, place of residence, jaw position, opposing dentition, number of implants, diameter and length of implants, abutment height and abutment angle were recorded. The survival rate of implants and marginal bone loss were calculated and analyzed. Cox proportional hazards ratio model was adopted to analyze the potential risk factors of prosthetic complications. Results: A total of 225 patients (288 jaws) and 1 260 implants were included, with 126 males and 99 females, aged (57.3±11.0) years, with a following time of (5.04±3.08) years. The 1-year cumulative survival rate of implants was 98.0% (1 235/1 260). Forty-eight implants were lost during the follow-up, with 39 implants in the maxillae and 9 implants in the mandible. The risk of implant failure of the maxillae ［7.2% （39/541）］ is significantly higher than that of the mandible ［1.3% （9/719）］ (P<0.01). Average marginal bone loss at 1 and 5 years was (0.7±0.2） mm and （1.1±0.3） mm. One hundred and twenty patients experienced prosthetic complications including screw/abutment loosening (44 cases), screw/abutment fracture (2 cases) and artificial tooth/denture base fracture (99 cases). The possibility of immediate prosthesis fracture within 6-8 months was high but declined over the following years with the final prosthesis delivered. Cox regression analysis showed that the use of 17° abutments in the anterior region was significantly related to the prosthetic complications （hazard ratio=1.797, P=0.002）. Conclusions: Immediate rehabilitation of the edentulous jaws with implant-supported full-arch prostheses can be a predictable technique. The immediate prosthetic mechanical complication prevalence was high. The use of 17° abutments in the anterior region may increase the risk of screw/abutment loosening. It is necessary to review in time.

[Quantitative three-dimensional methodology based on intraoral scan to assess the soft tissue contour alterations following single immediate implant and immediate provisionalization in maxillary central incisor: a 1-year prospective study]

Objective: To establish a quantitative three-dimensional method based on intraoral scan and apply it to evaluation of the facial soft tissue contour alterations following single immediate implant and immediate provisionalization (IIPP) in central incisor via intraoral scanning. Methods: This study was a prospective clinical study. The trial was conducted at Department of Implantology, Peking University School and Hospital of Stomatology, from January 2016 to September 2017. Twenty-nine eligible consecutive patients (15 women, 14 men) with a mean age of (34.3±12.0) were included and received immediate replacement of the failure maxillary single central incisor. A screw-retained immediate restoration was delivered for each patient. At 6-month follow-up, impression was taken and a screw-retained permanent restoration was performed for each patient. The anterior maxillary region was scanned by an intraoral scanning system at pre-surgery and 1-year follow-up. The Standard Tessellation Language (STL) files were output to a dedicated software and superimposed. Mid-facial recession and gingival zenith symmetry at 1-year follow-up were measured in the digital models. Three-dimensional configurations of the contour change volume were calculated and reconstructed for visual analysis. Furthermore, the following parameters were used to analyze the reconstructed volume: mean contour change in thickness (△d), mesio-distal width (D(W)), coronal-apical height (D(H)), contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site. Results: Twenty-seven out of twenty-nine enrolled patients were finally available for analysis. At 1-year follow-up, the mid-facial mucosa level at implant site was (0.23±0.39) mm apical to the gingival zenith of the contralateral tooth. In general, a contour collapse was found in every patient. △d, D(W) and D(H) of the collapsed volume were (0.62±0.22), (11.03±1.74) and (6.82±1.52) mm, respectively. Contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site were (0.54±0.48), (0.87±0.62), (1.03±0.46), (0.96±0.52), (0.90±0.52), (0.89±0.57) mm. Conclusions: The described quantitative measurement based on intraoral scan can be an effective method for assessment of soft tissue contour changes. At 1 year following single IIPP treatment in maxillary incisor, free gingival margin is stable, with only mild recession. The mean level of the facial soft tissue contour collapse is 0.62 mm.

[Complications of implant-supported full-arch immediate prosthesis: a retrospective analysis of 114 cases]

Objective: To evaluate the feasibility of long-term function of implant-supported full-arch immediate prosthesis via assessing the complications and risk factors. Methods: This historical cohort study included patients treated with implant-supported full-arch restoration under immediate loading protocol between April, 2008 to June, 2016 and wearing the immediate prosthesis for more than 6 months. Medical charts were reviewed for patients' general information, implant information, prosthetic information and details of prosthetic complications. COX proportional hazards ratio model was adopted to analyze the potential risk factors for prosthesis fracture. Results: A total of 114 patients with a mean age of (56.7±10.2) years old and 144 prostheses were included. The median wearing time of immediate prosthesis was 17.6 months. Sixty-two (54%) patients experienced prosthetic complication, 30 of them suffered more than once. Artificial teeth fractures were more common in anterior region while resin base fractured more often in the posterior region. The possibility of immediate prosthesis fracture in the first year was high but declined over the following years. COX regression analysis showed that fibre-reinforcement (HR=0.486, P=0.017) and rigid opposing dentition (HR=2.272, P=0.016) were significantly related to the prosthesis fracture. Conclusions: Long-term function of implant-supported full-arch immediate prosthesis renders a high prosthetic complication prevalence, featuring the prosthesis fracture as the most common complication and the first year of highest fracture probability. Fibre-reinforced acrylic immediate prosthesis may function well in cases with a removable denture restored opposing jaw.

[Lateral cephalometric analysis of patients with maxillary alveolar protrusion and advanced periodontitis treated with immediate implants and cross-arch fixed prostheses]

Objective: To investigate the changes of the lateral cephelometric landmarks of soft tissue and hard tissue of patients with maxillary alveolar protrusion and advanced periodontitis treated with immediate implants and cross-arch fixed prostheses. Methods: From January 2013 to October 2016, consecutive patients with advanced periodontitis and maxillary alveolar protrusion in need of immediate implants and cross-arch fixed prostheses were included in this study. All the patients were treated with provisional cross-arch fixed prostheses supported with 4 to 6 immediate implants after extraction of all the residual teeth and reduction of excessive alveolar bone. After 6 months, a final cross-arch fixed prosthesis was delivered. The lateral cephalometric landmarks of soft tissue and hard tissue at the time of pre-operation and final prosthesis delivery were analyzed. The change of patients' facial aesthetics was assessed using visual analogue scale (VAS). Results: Ten patients were included in the study. All the patients underwent full arch rehabilitation of both jaws supported by a total of 89 dental implants. In the maxillae, the average number of inserted implants were 4.5. The mean height of alveolar bone reduction was (6.3±1.8) mm. Both the distance of U1-NA (the upper incisor to nasion-A point line) and U1-PP (the upper incisor to palatal plane) were significantly reduced by (5.5±2.7) mm and (1.6±1.2) mm, respectively. The angle of U1-SN (between upper incisor to sella-nasion line) was reduced by 9.6°±8.1°palatally. The nasolabial angles were significantly increased by 10.5°±6.4°. Both the patients and dentists considered that the facial aesthetics was improved greatly after the treatment. Conclusions: With the reduction of excessive alveolar bone and the realignment of artificial teeth, the treatment of immediate implants and cross-arch fixed prostheses could improve the facial aesthetics of the patients with advanced periodontitis and maxillary alveolar protrusion.

[Systematic review and meta-analysis on the effect of implant supported overdentures on the oral health related quality of life of edentulous patients]

Objective: To evaluate the effect of implant related treatment on the oral health related quality of life (OHRQoL) of edentulous patients. Methods: The CNKI, Wanfang database and Medline, EMBASE, Cochrane Library databases that include randomized clinical trials comparing implant supported overdentures with conventional complete denture for edentulous patients were retrived. Nine studies involving 769 cases were included and meta-analysis was conducted. Results: The standardized mean difference (SMD) of oral health impact profile (OHIP) score was 1.63 (95%CI: 1.25-2.02) and improved after implant related treatment, which was significantly better than the conventional complete denture (0.87, 95% CI: 0.54-1.20). Conclusions: Implant supported overdentures improved patient's OHRQoL and showed better performance compared to the overdentures complete dentures.

[All-on-4 occlusion study: using T-Scan Ⅲ occlusal analysis system]

OBJECTIVE

To investigate the occlusal force distribution and the characteristics of the occlusion time of patients with All-on-4 rehabilitation at different occlusion position using T-Scan Ⅲ occlusal analysis system.

METHODS

Thirteen volunteers with All-on-4 rehabilitation were included in this study. T-Scan Ⅲ occlusal analysis system was used to measure the occlusal force distribution and the time character of the patients at intercuspal position, protrusive position, and lateral excursive position.

RESULTS

Maximum intercuspation: the left and right premolars took most of the occlusal force, namely (17.3±3.1)%, (15.8 ± 4.6)%, (15.5 ± 2.2)% and (15.2 ± 5.5)% (24, 25, 14, 15), the implants areas including the premolar and anterior teeth took (64.0±6.7)%, (19.2±8.0)% of occlusal force. The left and right sides took the respective percentages of (50.5±6.1)%, (49.5±6.1)%, and there was no difference. Protrusion position: the region (11, 12, 21, 22) commitment to take the percentage of (90.4±27.7)%. Occlusion time: 0.18(0.11, 0.26) s, disclusion time: 0.52 (0.35, 1.14) s . At the left and right lateral position, 8 patients were single teeth-supported occlusion, 5 patients were group fuctional occlusion, the average occlusion time was 0.20(0.13, 0.34) s, and DT was 1.07 (0.58, 1.46) s.

CONCLUSIONS

At maximum intercuspation: the implants areas including the premolar and anterior teeth were the occlusal force centers; the force concentrated in the area (11, 12, 21, 22) at the protrusion position. The lateral occlusal pattern shows multiformity.

The dirigent multigene family in Isatis indigotica: gene discovery and differential transcript abundance

BACKGROUND

Isatis indigotica Fort. is one of the most commonly used traditional Chinese medicines. Its antiviral compound is a kind of lignan, which is formed with the action of dirigent proteins (DIR). DIR proteins are members of a large family of proteins which impart stereoselectivity on the phenoxy radical-coupling reaction, yielding optically active lignans from two molecules of E-coniferyl alcohol. They exist in almost every vascular plant. However, the DIR and DIR-like protein gene family in I. indigotica has not been analyzed in detail yet. This study focuses on discovery and analysis of this protein gene family in I. indigotica for the first time.

RESULTS

Analysis of transcription profiling database from I. indigotica revealed a family of 19 full-length unique DIR and DIR-like proteins. Sequence analysis found that I. indigotica DIR and DIR-like proteins (IiDIR) were all-beta strand proteins, with a signal peptide at the N-terminus. Phylogenetic analysis of the 19 proteins indicated that the IiDIR genes cluster into three distinct subfamilies, DIR-a, DIR-b/d, and DIR-e, of a larger plant DIR and DIR-like gene family. Gene-specific primers were designed for 19 unique IiDIRs and were used to evaluate patterns of constitutive expression in different organs. It showed that most IiDIR genes were expressed comparatively higher in roots and flowers than stems and leaves.

CONCLUSIONS

New DIR and DIR-like proteins were discovered from the transcription profiling database of I. indigotica through bioinformatics methods for the first time. Sequence characteristics and transcript abundance of these new genes were analyzed. This study will provide basic data necessary for further studies.

¹³C tracer reveals phenolic acids biosynthesis in hairy root cultures of Salvia miltiorrhiza

Rosmarinic acid (RA) and lithospermic acid B (LAB) are two typical phenolic acids with significant bioactivities that may contribute to the therapeutic effects of Salvia miltiorrhiza. Precise knowledge of the biosynthetic pathway leading to RA and LAB is a necessary prerequisite to optimize the production of important phenolic compounds in S. miltiorrhiza. In vivo isotopic labeling experiments using [ring-(13)C]-phenylalanine, combined with dynamic measurements of metabolite levels by UPLC/Q-TOF, were used to investigate the metabolic origin of phenolic acids in S. miltiorrhiza. These data indicate the in vivo phenolic biosynthetic pathway: two intermediates from the general phenylpropanoid pathway and the tyrosine-derived pathway, 4-coumaroyl-CoA and 3,4-dihydroxyphenyllactic acid (DHPL), are coupled by the ester-forming enzyme rosmarinic acid synthase (SmRAS) to form 4-coumaroyl-3',4'-dihydroxyphenyllactic acid (4C-DHPL). The 3-hydroxyl group is introduced late in the pathway by a cytochrome P450-dependent monooxygenase (SmCYP98A14) to form RA. Subsequently, RA is transformed to a phenoxyl radical by oxidation, and two phenoxyl radicals unite spontaneously to form LAB. The results indicate aspects of the complexity of phenolic acid biosynthesis in S. miltiorrhiza and expand an understanding of phenylpropanoid-derived metabolic pathways. The candidate genes for the key enzymes that were revealed provide a substantial foundation for follow-up research on improving the production of important phenolic acids through metabolic engineering in the future.

Overexpression of allene oxide cyclase promoted tanshinone/phenolic acid production in Salvia miltiorrhiza

KEY MESSAGE

This study provides a desirable candidate gene resource (SmAOC) to increase the content of valuable natural products via appropriate JA pathway genetic engineering. Jasmonates (JAs) are important signal molecules in plants. They regulate transcripts of defense and secondary biosynthetic metabolite genes in response to environmental stresses. Currently, JAs are widely used as elicitors to improve the content of useful secondary metabolism in plants. Synthesis of the naturally occurring enantiomer of various jasmonates is catalyzed by allene oxide cyclase (AOC, EC 5.3.99.6). Here, we cloned and characterized the AOC gene (SmAOC) from Salvia miltiorrhiza. As expected, SmAOC expression was induced by abiotic stimuli such as methyl jasmonate (MeJA), ultraviolet radiation (UV) and low temperature (4 °C) in S. miltiorrhiza plantlets. To demonstrate whether the engineered internal JAs pool by overexpressing AOC gene could promote secondary metabolism production, the SmAOC was incorporated into S. miltiorrhiza hairy roots. The results revealed that SmAOC overexpression significant enhanced the yields of tanshinone IIA, rosmarinic acid (RA) and lithospermic acid B (LAB) in S. miltiorrhiza hairy roots. In addition, expression levels for key genes involved in the biosynthetic pathway of diterpenes and phenolic acids were also altered. These suggest that genetic manipulation of AOC would be helpful for improving the production of valuable secondary metabolites by regulating the biosynthesis of JAs.

The c4h, tat, hppr and hppd genes prompted engineering of rosmarinic acid biosynthetic pathway in Salvia miltiorrhiza hairy root cultures

Rational engineering to produce biologically active plant compounds has been greatly impeded by our poor understanding of the regulatory and metabolic pathways underlying the biosynthesis of these compounds. Here we capitalized on our previously described gene-to-metabolite network in order to engineer rosmarinic acid (RA) biosynthesis pathway for the production of beneficial RA and lithospermic acid B (LAB) in Salvia miltiorrhiza hairy root cultures. Results showed their production was greatly elevated by (1) overexpression of single gene, including cinnamic acid 4-hydroxylase (c4h), tyrosine aminotransferase (tat), and 4-hydroxyphenylpyruvate reductase (hppr), (2) overexpression of both tat and hppr, and (3) suppression of 4-hydroxyphenylpyruvate dioxygenase (hppd). Co-expression of tat/hppr produced the most abundant RA (906 mg/liter) and LAB (992 mg/liter), which were 4.3 and 3.2-fold more than in their wild-type (wt) counterparts respectively. And the value of RA concentration was also higher than that reported before, that produced by means of nutrient medium optimization or elicitor treatment. It is the first report of boosting RA and LAB biosynthesis through genetic manipulation, providing an effective approach for their large-scale commercial production by using hairy root culture systems as bioreactors.

Molecular characterization, recombinant expression in Escherichia coli and biological activity of (S)-Tetrahydroberberine oxidase from Corydalis saxicola Bunt

(S)-Tetrahydroberberine [(S)-THB] oxidase is the last enzyme of benzylisoquinoline alkaloids pathway which catalyzes the dehydrogenation of four hydrogen atoms of (S)-THB to produce berberine, the final step of berberine biosynthesis. A (S)-THB gene, designated as Cs(S)-THBO (Genbank accession No. HQ393909), was cloned from a Corydalis saxicola cDNA library by rapid amplification of cDNA ends. The full-length of cDNA of Cs(S)-THBO was 1127 bp with an open reading frame of 699 bp that predicted to encode a 232-amino acid polypeptide, with a predicted molecular mass of 25.20 kDa. Cs(S)-THBO was the first (S)-THBO gene found in C. saxicola. Real-time quantitative PCR analysis indicated that Cs(S)-THBO was constitutively expressed in roots, stems, leaves and flowers of C. saxicola, and with the highest expression level in roots. The results of treatment experiment for plant defense responses revealed that expression of Cs(S)-THBO had a prominent diversity. Recombinant Cs(S)-THBO protein expressed in Escherichia coli strain BL21 (DE3) was active. The results of feeding experiment and HPLC-DAD-ESI-MS(n) analysis showed that Cs(S)-THBO had the function of catalyzing (S)-tetrahydroberberine to berberine.

IiSDD1, a gene responsive to autopolyploidy and environmental factors in Isatis indigotica

In plants, stomata play a pivotal role in the regulation of gas exchange and are distributed throughout the aerial epidermis. SDD1, a gene isolated from Arabidopsis thaliana has been demonstrated to specialize in stomatal density and distribution. In our present study, a comprehensive survey of global gene expression performed by using an A. thaliana whole genome Affymetrix gene chip revealed SDD1 tends to be significantly lower in tetraploid Isatis indigotica than in diploid ones. To intensively investigate different SDD1 expression in response to polyploidy, a full-length cDNA clone (IiSDD1) encoding SDD1 was isolated from the traditional Chinese medicinal herb I. indigotica cDNA library. IiSDD1 shared a high level of identity with that from A. thaliana, containing some basic features of subtilases: D, H and S regions, as well as a substrate-binding site. Real-time quantitative PCR analysis indicated that IiSDD1 was constitutively expressed in all tested tissues, including roots, stems and leaves, both in tetraploid and diploid I. indigotica, and with the highest expression in leaves. In addition, IiSDD1 was also found to be down-regulated by signalling molecules for plant defence responses, such as abscisic acid (100 microM) and gibberellin (100 mg/L), as well as by environmental stresses including salt, darkness, coldness and drought. Our study, for the first time, indicates SDD1 participates not only in the defense/stress responsive pathways, but also probably involves in plants polyploidy evolution.

Lithospermic acid B is more responsive to silver ions (Ag+) than rosmarinic acid in Salvia miltiorrhiza hairy root cultures

LAB (lithospermic acid B) is a dimer of RA (rosmarinic acid) and has been suggested to be derived from RA, but the detailed biosynthesis process has not yet been identified. The accumulation of RA has been intensively investigated in the plant species of Boraginaceae and Lamiaceae. In the present study, we report that silver ions (Ag+; 15 microM), an abiotic elicitor, did not stimulate RA accumulation but dramatically enhanced LAB from approx. 5.4% to 18.8% of dry weight in Salvia miltiorrhiza hairy root cultures, and the rise in LAB was found to be coincident with the decline of RA content at each time point after treatment. Meanwhile, a profiling analysis of genes and metabolites (intermediates) involved in the RA synthesis pathway was performed; the result indicated that several gene transcripts and metabolite accumulations show temporal changes in abundance consistent with LAB production. Thus a potential (putative) biosynthetic route from RA to LAB was presumed, which was suggested to be significantly activated by Ag+ in S. miltiorrhiza hairy root cultures. Further intermediate monitoring and compound feeding experiments were performed to rank the strength of this hypothesis. Our study, for the first time, provides evidence that RA is a precursor leading to LAB synthesis.

Methyl jasmonate dramatically enhances the accumulation of phenolic acids in Salvia miltiorrhiza hairy root cultures

The aim of this work was to examine rosmarinic acid and its derivative lithospermic acid B accumulation, as well as related gene transcript and metabolite profiling in Salvia miltiorrhiza Bunge (Lamiacae) hairy root cultures, in response to methyl jasmonate (0.1 mM). Results showed methyl jasmonate dramatically enhanced both rosmarinic acid and lithospermic acid B accumulation, from approximately 3.25 to 6.02%, and 2.94 to 19.3% of dry weight, respectively. Meantime, several rosmarinic acid biosynthetic gene transcripts were coordinately induced, with phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase, tyrosine aminotransferase, 4-hydroxyphenylpyruvate reductase and 4-hydroxyphenylpyruvate dioxygenase transcripts displaying the most rapid and substantial increases. Liquid chromatographic-tandem mass spectrometry was used to characterize the profile of metabolites involved in rosmarinic acid biosynthesis pathway, in both control and elicited-treated hairy root cultures. Further canonical correlation analysis constructed a gene-to-metabolite network, locating possible gene candidates which would directly link to phenolic acids (rosmarinic acid and lithospermic acid B) production, and thereby, would help to prompt the possibility of a key gene-based metabolic engineering for the synthesis of active pharmaceutical compounds in S. miltiorrhiza.

Characterization and expression profiling of 4-hydroxyphenylpyruvate dioxygenase gene (Smhppd) from Salvia miltiorrhiza hairy root cultures

A novel 4-hydroxyphenylpyruvate dioxygenase gene (designated as Smhppd) was cloned from hairy roots of Salvia miltiorrhiza Bung. The full-length cDNA of Smhppd was 1,736 bp long with an ORF (open reading frame) that putatively encoded a polypeptide of 481 amino acids, with a predicted molecular mass of 52.54 kDa. The deduced amino acid sequence of the Smhppd gene shared high homology with other known HPPDs. Analysis of Smhppd genomic DNA revealed that it contained two exons and one intron. The analysis of Smhppd promoter region was also presented. Southern-blot analysis revealed that the Smhppd was a low-copy gene in S. miltiorrhiza. Real-time quantitative PCR analysis indicated that Smhppd was constitutively expressed in roots, stems and leaves of S. miltiorrhiza, with the high expression in roots. In addition, Smhppd expression level under different stress condition was also analyzed during the hairy root culture period, including signaling components for plant defence responses, such as methyl jasmonate and salicylic acid, as well as an abiotic elicitor, Ag(+) and a biotic elicitor, yeast extract. This study will enable us to further understand the role Smhppd plays in the synthesis of active pharmaceutical compounds in S. miltiorrhiza at molecular level.

Investigation of polychlorinated biphenyl removal from contaminated soil using microwave-generated steam

A feasibility study of polychlorinated biphenyl (PCB) removal from contaminated soils using microwave-generated steam (MGS) was performed. Initial experimental results show that MGS effectively removed PCBs from contaminated soil with an overall removal efficiency of greater than 98% at a steam-to-soil mass ratio of 3:1. Removal efficiency was found to be dependent upon the amount of steam employed, expressed as a mass ratio of steam applied to soil mass. Evaporation was identified as a major mechanism in removing PCBs from the soil. Rapid expansion and evaporation of pore water by microwave dielectric heating accelerated evaporation rates of PCB molecules. Increased solubility of PCBs into the heated aqueous phase is also hypothesized. Together these effects increase mass-transfer rates, thus enhancing removal of PCBs from the soil.

The anatomy of the lateral cutaneous nerve of the thigh--a possible donor nerve for facial nerve repair

One hundred anterior branches of the lateral cutaneous nerve of the thigh were dissected and measured in 50 adult cadavers. The results show that this nerve was present in all sides, and the average length from the point of the nerve piercing the fascia lata to the point of its first branch was about 79 mm, the average width was 2.25 mm, and the average thickness was 0.79 mm. It was found that the nerve was approximately along the line between the anterior superior iliac spine and the midpoint of the upper margin of the patella. This study presents a simple method of locating this nerve for clinical reference. The results also reveal that this nerve is a possible donor for facial nerve repair.