Objective To explore the action mechanism of long non-coding RNA(lncRNAs)lncRNA KCTD13-DT in oral squamous cell carcinoma(OSCC)and its potential interaction with transcription factor c-Myc,providing a potential diagnostic and therapeutic target for patients with OSCC.Methods The expression of lncRNA KCTD13-DT in OSCC and paracancerous tissues was detected by qRT-PCR.The effects of c-Myc overexpression and knock-down on human tongue squamous carcinoma cells HN6 and CAL27 were detected by qRT-PCR.Fluorescence in si-tu hybridization(FISH)assessed the localization of lncRNA KCTD13-DT in cells.A dual luciferase reporter gene was used to analyze the role of c-Myc in target binding to the promoter region of lncRNA KCTD13-DT.Stable cell lines with knockdown or overexpression of lncRNA KCTD13-DT were constructed in human OSCC cell lines HN6 and CAL27 by lentiviral infection,and the knockdown and overexpression efficiencies of lncRNA KCTD13-DT were detected by qRT-PCR.Cell proliferation changes were detected by growth curve assay,CCK-8 assay,colony forma-tion assay,and cell migration was detected by scratch assay and Transwell.Results lncRNA KCTD13-DT expres-sion level was reduced in OSCC tissues and OSCC cells(HN6,CAL27),and Western blot verified that after knoc-king down and overexpression of c-Myc in HN6 and CAL27,the qRT-PCR experiments showed that c-Myc nega-tively regulated lncRNA KCTD13-DT,and overexpression of c-Myc significantly down-regulated lncRNA KCTD13-DT;knockdown of c-Myc significantly up-regulated lncRNA KCTD13-DT levels.Dual luciferase reporter gene showed that c-Myc could target lncRNA KCTD13-DT,and c-Myc could be involved in regulating and repressing the transcriptional activity of lncRNA KCTD13-DT.FISH showed that lncRNA KCTD13-DT mainly existed in the nu-cleus.Growth curve assay,CCK-8 assay,cell scratch assay,Transwell,and colony formation assay showed that knockdown of lncRNA KCTD13-DT promoted the growth and proliferation of OSCC cells,and overexpression of ln-cRNA KCTD13-DT significantly inhibited the proliferation and migration of OSCC cells.Conclusion lncRNA KCTD13-DT is negatively regulated by c-Myc.Knockdown of lncRNA KCTD13-DT promotes cell proliferation,while overexpression of it inhibits cell growth.

Objective : To explore the effects of different implant sites combined with pterygomaxillary implantation on the biomechanics of implant and bone tissue，and to provide a basis for clinical selection of implant design in accordance with biomechanical principles． Methods: The cone-beam CT scan data of an edentulous maxillary with inadequate posterior bone were selected to complete the establishment of the three-dimensional entity model of the maxilla．The prosthesis and implant-abutment integrated three-dimensional entity models were established using the prosthesis and implant data ，and five groups of three-dimensional finite element models of different implant sites were designed．A unilateral vertical load of 200 N and an oblique load of 100 N were applied to the bilateral posterior dental area，respectively．ANSYS finite element analysis software was used to calculate the stress distribution on the surface of the implant and surrounding bone tissue．SPSS 26. 0 software package was used to statistically analyze the data. Results : ① All the five models showed that the maximum stress was concentrated in the neck of the implants and cortical bone. ② The maximum stress value of the implant under oblique loading was greater than that under vertical loading (P＜0. 05) ，but there was no significant difference in the maximum stress value around bone tissue in the 5 groups of models. ③ There was no significant difference in the maximum stress of the implant and bone between the different implant sites combined with pterygomaxillary implants． Conclusion In the fixed restoration of maxillary edentulous implants，pterygomaxillary implants implanted symmetrically on both sides and changing the position point of the anterior implant do not affected the stress distribution of the whole design．In clinical practice，suitable sites can be selected according to the residual bone mass of patients，and combined with pterygomaxillary implantation for implant design.

Objective:To investigate the efficacy and safety of SIMPLE regimen in the treatment of extranodal NK/T-cell lymphoma (ENKTCL).Methods:The clinical data of 11 patients with ENKTCL who were admitted to the University of Hong Kong-Shenzhen Hospital from January 2012 to January 2022 were retrospectively analyzed. The patients received 4-6 courses of SIMPLE (cisplatin, gemcitabine, ifosfamide, etoposide, dexamethasone, and pegasparaginase) regimen chemotherapy, and stage Ⅰ and Ⅱ patients who also received local radiotherapy after 2 or 3 courses of chemotherapy. Patients were evaluated for mid-treatment and end-of-treatment outcomes, and the adverse effects of patients were evaluated in each treatment cycle. The Kaplan-Meier method was used to analyze the progression-free survival (PFS) and overall survival (OS) of the 11 patients.Results:All 11 patients were nasal type, with the median age of 41 years old (26-67 years old), including 5 males and 6 females, 3 relapsed cases and 8 newly treated cases. Of the 10 patients evaluated for efficacy, 9 achieved complete remission and 1 achieved at least partial remission (efficacy was assessed based on follow-up). All 11 patients were followed up for a median time of 50 months (15-72 months) and 2 relapsed patients died due to disease progression. The expected 5-year PFS rate and OS rate of 11 patients were both 90.0%, and the expected 5-year OS rate was 100.0% and 66.6% in newly treated and relapsed patients, respectively. Common adverse effects were hematologic adverse reactions, infections, gastrointestinal symptoms, elevated transaminases, and hypofibrinogenemia, all of which were curable. There is no treatment-related death.Conclusions:The SIMPLE regimen for the treatment of ENKTCL has a high remission rate, the patients have long survival time, and the regimen is moderately well tolerated.

BACKGROUND: Regenerative medicine by using stem cells from dental pulp is promising for treating patients with critical limb ischemic (CLI). Here, we investigated the difference in the angiogenetic ability of stem cells from human exfoliated deciduous teeth (SHED) and human dental pulp stem cells (DPSC). METHODS: SHED and DPSC were harvested from dental pulp and analyzed in flow- cytometry for detecting the expression of surface markers. Levels of angiogenetic marker were examined by RT-PCR and Western-blot. Eighteen immunodeficient mice of critical limb ischemic model were divided into three groups: SHED, DPSC and saline, which was administered with SHED, DPSC or saline intramuscularly. Histological examination was performed to detect the regenerative results. RESULTS: A highly expression of CD146 was detected in SHED. Moreover, cells with negative expression of both CD146 and CD31 in SHED were more in comparison with those in DPSC. Expression of angiogenesis factors including CXCL12, CXCR4, Hif-1a, CD31, VEGF and bFGF were significant higher in SHED than DPSC by the RT-PCR and Western-Blot results. SHED induced more CD31 expression and less fibrous tissue formation in the critical limb ischemic model as compare with DPSC and saline. CONCLUSION Both SHED and DPSC possessed the ability of repairing CLI. With expressing more proangiogenesis factors, SHED may have the advantage of repairing CLI.

BACKGROUND: The role of sex hormones and their receptors has drawn much attention in the process of cartilage regeneration. This study aimed to investigate the effect of androgen receptor (AR) on the chondrogenic ability of articular chondrocytes and the related mechanism. METHODS: Articular chondrocytes were isolated, cultured, identified by toluidine blue staining and then transduced with lentivirus carrying the AR gene. The cell viability was determined using Cell Counting Kit-8, and cell apoptosis was assessed by flow cytometry analysis. The effects of AR overexpression on the expression of cartilage-specific proteins and some signalling molecules were evaluated by real-time PCR and Western blotting. Using 24 New Zealand rabbits, the regeneration of rabbit articular cartilage defects was further investigated in vivo and evaluated histologically. RESULTS: The overexpression of AR significantly reduced the apoptosis rate of chondrocytes but did not affect their proliferation. The overexpression of AR also promoted the expression of Sry-related HMG box 9, collagen II and aggrecan, decreased the expression of matrix metalloproteinase-13, and downregulated p-S6 and RICTOR. The experimental group with AR-overexpressing chondrocytes exhibited superior regeneration of cartilage defects. CONCLUSION AR overexpression can maintain the phenotype of chondrocytes and promote chondrogenesis in vitro and in vivo. mTOR-related signalling was inhibited.

BACKGROUND: The role of sex hormones and their receptors has drawn much attention in the process of cartilage regeneration. This study aimed to investigate the effect of androgen receptor (AR) on the chondrogenic ability of articular chondrocytes and the related mechanism. METHODS: Articular chondrocytes were isolated, cultured, identified by toluidine blue staining and then transduced with lentivirus carrying the AR gene. The cell viability was determined using Cell Counting Kit-8, and cell apoptosis was assessed by flow cytometry analysis. The effects of AR overexpression on the expression of cartilage-specific proteins and some signalling molecules were evaluated by real-time PCR and Western blotting. Using 24 New Zealand rabbits, the regeneration of rabbit articular cartilage defects was further investigated in vivo and evaluated histologically. RESULTS: The overexpression of AR significantly reduced the apoptosis rate of chondrocytes but did not affect their proliferation. The overexpression of AR also promoted the expression of Sry-related HMG box 9, collagen II and aggrecan, decreased the expression of matrix metalloproteinase-13, and downregulated p-S6 and RICTOR. The experimental group with AR-overexpressing chondrocytes exhibited superior regeneration of cartilage defects. CONCLUSION AR overexpression can maintain the phenotype of chondrocytes and promote chondrogenesis in vitro and in vivo. mTOR-related signalling was inhibited.

Objective: To study the clinical outcomes of implanting platelet rich fibrinogen (PRF) mixed with Bio-Oss® in the extraction socket for alveolar ridge preservation and to provide evidence for clinical application. Methods: Thirty-six patients who underwent alveolar ridge preservation were enrolled. Thirty-six extraction sites were divided into two groups: PRF mixed with Bio-Oss® group (test group) and Bio-Oss® alone (control group). Bone dimensional changes in height and width were measured by CBCT before and 6 months after surgery, and early soft tissue healing and postoperative pain sensation were evaluated clinically 1 week after surgery. Results : There was no significant difference in the alveolar bone height (-1.48 ± 0.40) mm between the test group and the control group. The difference in the alveolar bone width between the test group (-1.09 ± 0.42) mm and the control group (-1.35 ± 0.22) mm was statistically significant (z=-2.63, P=0.01). The postoperative pain score of the test group was 2.39 ± 1.20, and that of the control group was 3.39 ± 1.65, the difference was statistically significant (t=-2.083, P=0.045). There was no significant difference in soft tissue healing between the test group and the control group. Conclusion The use of PRF mixed with Bio-Oss ®in the alveolar ridge preservation procedure can reduce alveolar bone absorption and postoperative pain.

Objective: To explore the effects of dendritic epidermal T cells (DETC) on proliferation and apoptosis of epidermal cells in wound margin of mice and its effects on wound healing. Methods: Twenty-eight healthy specific pathogen free (SPF) C57BL/6 wild-type (WT) male mice aged 8-12 weeks and 60 SPF T lymphocyte receptor δ-knockout (TCR δ^-/-) male mice aged 8-12 weeks were selected to conduct the following experiments. (1) Eight WT mice were selected to isolate epidermal cells and primarily culture DETC according to the random number table. Morphological observation and purity identification of DETC by flow cytometer were detected immediately after culture and on culture day (CD) 15 and 30, respectively. (2) According to the random number table, 5 WT mice and 5 TCR δ^-/- mice were selected and enrolled into WT control group and TCR δ^-/- group. Round full-thickness skin defect with diameter of 6 mm was made on the back of each mouse. The wound healing condition was observed immediately after injury and on post injury day (PID) 2, 4, 6, 8, 10, and the percentage of residual wound area was calculated. (3) Mice were selected to group and reproduce model of full-thickness skin defect as in experiment (2). On PID 3, the tissue of wound margin was collected for hematoxylin eosin staining, and the length of new epithelium was measured. (4) Mice were selected to group and reproduce model of full-thickness skin defect as in experiment (2). On PID 3, epidermal tissue of wound margin was collected to determine expression of proliferating cell nuclear antigen (PCNA) using Western blotting for evaluation of proliferation of epidermal cell. (5) Mice were selected to group and reproduce model of full-thickness skin defect as in experiment (2). On PID 3, epidermal tissue of wound margin was selected and digested into single-cell suspension, and apoptosis of cells was detected by flow cytometer. (6) Forty TCR δ^-/- mice were selected to carry out the same treatment as in experiments (2)-(5). According to the random number table, these mice were enrolled into TCR δ^-/- control group and TCR δ^-/-+ DETC group, with 5 mice in each group for each experiment. Round full-thickness skin defect was made on the back of each mouse. DETC in the number of 1×10⁵ (dissolution in 100 μL phosphate with buffer purity above 90%) were injected through multiple points of wound margin of mice in TCR δ^-/-+ DETC group immediately after injury, and equal volume of phosphate buffer was injected into mice of TCR δ^-/- control group with the same method as above. Data were processed with one-way analysis of variance for repeated measurement, t test, and Bonferroni correction. Results: (1) Along with the culture time elapse, the number of dendritic structures of DETC increased gradually. The percentage of T lymphocytes was 4.67% and 94.1% of these T lymphocytes were DETC. The purity of DETC on CD 15 was 18.50% and the purity of DETC on CD 30 was 98.70%. (2) Immediately after injury, the wound healing condition of mice in WT control group and TCR δ^-/- group was similar. The wound healing speed of mice in TCR δ^-/- group was slower than that in WT control group on PID 2-10. The percentages of residual wound area of mice in TCR δ^-/- group on PID 2, 4, 6, 8, and 10 were increased significantly compared with those in WT control group (t=3.492, 4.425, 4.170, 4.780, 7.318, P<0.01). (3) The length of new epithelium of mice in TCR δ^-/- group on PID 3 was (359 ± 15) μm, which was obviously shorter than that in WT control group [(462±26) μm, t=3.462, P<0.01]. (4) Immediately after injury, wound condition of mice in TCR δ^-/-+ DETC group and TCR δ^-/- control group was similar. Compared with TCR δ^-/-+ DETC group, the wound healing speed of mice in TCR δ^-/- control group were obviously slower on PID 2-10. The percentages of residual wound area of mice in TCR δ^-/-+ DETC group on PID 2, 4, 6, 8, and 10 were decreased significantly compared with those in TCR δ^-/- control group (t=2.308, 3.725, 2.698, 3.707, 6.093, P<0.05 or P<0.01). (5) On PID 3, the length of new epithelium of mice in TCR δ^-/-+ DETC group was (465±31) μm, which was obviously longer than that in TCR δ^-/- control group [(375±21) μm, t=2.390, P<0.05]. (6) On PID 3, PCNA expression of epidermal cell in wound margin of mice in TCR δ^-/- group was 1.25±0.04, which was obviously lower than that in WT control group (2.01±0.09, t=7.415, P<0.01). (7) On PID 3, PCNA expression of epidermal cell in wound margin of mice in TCR δ^-/-+ DETC group was 1.62±0.08, which was significantly higher than that in TCR δ^-/- control group (1.05±0.14, t=3.561, P<0.05). (8) On PID 3, apoptosis rate of epidermal cell in wound margin of mice in TCR δ^-/- group was (16.1±1.4)%, which was higher than that in WT control group [(8.1±0.6)%, t=5.363, P<0.01]. (9) On PID 3, apoptosis rate of epidermal cell in wound margin of mice in TCR δ^-/-+ DETC group was (11.4±1.0)%, which was obviously lower than that in TCR δ^-/- control group [(15.4±1.4)%, t=2.377, P<0.05]. Conclusions DETC participates in the process of wound healing though promoting the proliferation of epidermal cells in wound margin and inhibit the apoptosis of these cells.

Coronavirus disease 2019 (COVID-19) outbroke in Wuhan, China in December 2019 and the severe acute respiratory syndrome (SARS) outbroke in Guangzhou, China in 2003 were caused by highly pathogenic coronaviruses with high homology. Since the 2019 novel coronavirus is highly contagious and spreads rapidly. It has caused negative social effects and massive economic loss globaly. Currently there is no vaccine or effective drugs. Pulmonary fibrosis is a pulmonary disease with progressive fibrosis, which is the main factor leading to pulmonary dysfunction and declined quality of life in SARS survivors after recovery. Extensive epidemiological, viral immunological and current clinical evidences support the possibility that pulmonary fibrosis may be one of the major complications in COVID-19 patients. At present there is no report on the mechanism by which COVID-19 induces pulmonary fibrosis.With the existing theoretical basis, this article focuses on discussing the possible mechanism of COVID-19 sustained lung damaging, the key role of abnormal immune mechanism in the initiation and promotion of pulmonary fibrosis, and the corresponding therapeutic measures.

Objective:To explore the mechanism of dendritic epidermal T lymphocytes (DETCs) in promoting healing of full-thickness skin defect wound on mice by regulating the proliferation and differentiation of epidermal stem cells (ESCs) in mice.Methods:(1) Ten 8-week-old wild type (WT) male C57BL/6 mice (the same sex and kind below) were sacrificed to collect the skin of back for extracting DETCs to culture. Five WT and five 8-week-old T cell receptor (TCR) δ -/ - mice were selected and enrolled in WT control group and TCR δ -/ - control group, respectively. A full-thickness skin defect wound with diameter of 6 mm was made on both sides of spinal line on the back of mice without any treatment after injury. Another fifteen 8-week-old TCR δ -/ - mice were selected and divided into phosphate buffer solution (PBS), DETC, and insulin-like growth factor-Ⅰ(IGF-Ⅰ) groups according to the random number table (the same grouping method below), with 5 mice in each group, and the same full-thickness skin defect wound was made on each mouse. Immediately after injury, mice in PBS, DETC, and IGF-Ⅰ groups were injected subcutaneously around each wound with 10 μL sterile PBS , DETCs (cell concentration of 1×10 6/mL), and 5 mg/mL recombinant mice IGF-Ⅰ, respectively. The percentage of the residual wound area was calculated on post injury day (PID) 2, 4, 6, and 8. (2) Three 8-week-old WT mice were enrolled in WT control group and nine 8-week-old TCR δ -/ - mice were divided into TCR δ -/ - control group, PBS group, and DETC group, with 3 mice in each group. The full-thickness skin defect wound was made as in experiment (1) . On PID 3, the protein expression of IGF-Ⅰ in the epidermis tissue of wound margin was detected by chemiluminescence imaging analyzer. (3) Three 8-week-old WT mice were enrolled in WT control group and six 8-week-old TCR δ -/ - mice were divided into PBS and DETC groups, with 3 mice in each group, and the full-thickness skin defect wound was made as in experiment (1). On PID3, DETCs were extracted from the wound margin epidermis tissue to detect the percentage of DETCs expressing IGF-Ⅰ by flow cytometer. (4) The mice were taken as in experiment (2) and divided into WT control, PBS, DETC, and IGF-Ⅰ groups. A straight full-thickness skin defect incision with length of 3 cm was made in the direction of one inner ear. Mice in WT control group didn′t have any other treatment after injury, and immediately after injury, mice in PBS, DETC, and IGF-Ⅰ groups were injected subcutaneously around each wound with 10 μL sterile PBS, DETCs (cell concentration of 1×10 6/mL), and 5 mg/mL recombinant mice IGF-Ⅰ, respectively. On PID 12, epidermis tissue of wound margin was collected, and immunofluorescence staining was performed to observe the number of keratin 15 positive cells. (5) The same mice were collected, grouped, and treated as in experiment (4). On PID12, the epidermis tissue of wound margin was collected and immunofluorescence staining was performed to observe the number of keratin 10 positive cells. (6) Twenty 3-day-old WT mice (the same below) were sacrificed to collect the whole skin, which was used to extract ESCs, with 5 mice detecting one index. The ESCs were divided into DETC co-culture group and control group, which were added with 1 mL DETCs (cell concentration of 1.25×10 6/mL) and DETC medium, respectively. The percentage of 5-ethynyl-2′-deoxyuridine (EdU) positive cell on culture day (CD) 3, the percentages of CD49f + CD71 - and keratin 14 positive cells on CD 5, and the percentage of keratin 10 positive cell on CD 10 in 2 groups were detected by flow cytometer. (7) Twenty mice were taken to extract ESCs, with 5 mice detecting one index. The ESCs were divided into control group and IGF-Ⅰ group, which were added with 1 mL sterile PBS and 10 ng/mL recombinant mice IGF-Ⅰ, respectively. The percentages of EdU positive cell, CD49f + CD71 - cell, keratin10 positive cell, and keratin 14 positive cell were detected as in experiment (6). The sample in each group of experiments (6) and (7) was three. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and t test. Results:(1) On PID 4, 6, and 8, the percentage of residual wound area in TCR δ -/ - control group was significantly higher than that in WT control group ( t=2.78, 3.39, 3.66, P<0.05 or P<0.01). The percentage of residual wound area in DETC group and IGF-Ⅰgroup on PID 4, 6, and 8 was apparently lower than that in PBS group ( t=2.61, 3.21, 3.88, 2.84, 2.91, 2.49, P<0.05 or P<0.01). (2) On PID 3, the protein expression of IGF-Ⅰ in the epidermis tissue of wound margin of mice in TCR δ -/ - control group was significantly lower than that in WT control group ( t=17.34, P<0.01). The protein expression of IGF-Ⅰ in the epidermis tissue of wound margin of mice in DETC group was significantly higher than that in PBS group ( t=11.71, P<0.01). (3) On PID 3, the percentage of DETCs expressing IGF-Ⅰ in the epidermis tissue of wound margin of mice in PBS group was significantly lower than that in WT control group and DETC group ( t=24.95, 27.23, P<0.01). (4) On PID 12, the number of keratin 15 positive cells in the epidermis tissue of wound margin of mice in PBS group was significantly lower than that in WT control group, DETC group, and IGF-Ⅰ group ( t=17.97, 11.95, 7.63, P<0.01). (5) The number of keratin 10 positive cells in the epidermis tissue of wound margin of mice in PBS group was significantly higher than that in WT control group, DETC group, and IGF-Ⅰ group ( t=11.59, 9.51, 3.48, P<0.05 or P<0.01). (6) The percentages of EdU positive cells on CD 3, CD49f + CD71 - cells on CD 5, and keratin 14 positive cells on CD 5 in DETC co-culture group were respectively (43.5±0.6)%, (66.5±0.5)%, (69.3±1.7)%, apparently higher than (32.3±1.3)%, (56.4±0.3)%, (54.9±1.3)% in control group ( t=7.97, 17.10, 6.66, P<0.01). The percentage of keratin 10 positive cells on CD 10 in DETC co-culture group was (55.7±0.7)%, significantly lower than (67.1±1.2)% in control group ( t=8.34, P<0.01). (7) The percentages of EdU positive cells on CD 3, CD49f + CD71 - cells on CD 5, and keratin 14 positive cells on CD 5 in IGF-Ⅰ group were respectively (42.1±0.9)%, (81.1±1.3)%, (66.8±1.0)%, apparently higher than (32.4±0.7)%, (74.9±0.7)%, (52.0±1.9)% in control group ( t=8.39, 4.24, 7.25, P<0.05 or P<0.01). The percentage of keratin 10 positive cells on CD 10 in IGF-Ⅰ group was (53.5±1.1)% , significantly lower than (58.2±0.3)% in control group ( t=3.99, P<0.05). Conclusions:DETCs can promote the proliferation and anti-apoptotic potential of ESCs and inhibit their differentiation into end-stage by secreting IGF-Ⅰ, thus promoting wound healing of full-thickness skin defects in mice.