Clinical cell-based versus cell-free regenerative endodontics: clarification of concept and term.

There is no consensus on the true meaning of clinical regenerative endodontics, and there is confusion over the concept and the term. Commonly used terms include revitalization and revascularization. The clinical methods for endodontic revitalization procedures and the tissue engineering concept differ depending on whether there is exogenous delivery of cells - called cell therapy, or not. Here, in this review, the difference is clarified by emphasizing the correct terminology: cell-free versus cell-based regenerative endodontic therapy (CF-RET versus CB-RET). The revitalization procedures practised clinically do not fit into the modern tissue engineering concepts of pulp regeneration but can be categorized as CF-RET. The modern tissue engineering concept in pulp regeneration is a CB-RET, which so far is at the clinical trial stage. However, histological examination of teeth following regenerative endodontic treatments reveals healing with repair derived from stem cells that originate from the periodontal, bone and other tissues. The aim of regenerative endodontics is regeneration of the pulp-dentine complex. This review discusses why CF-RET is unlikely to regenerate a pulp-dentine complex with current protocols. The American Association of Endodontists and the European Society of Endodontology have not yet recommended autologous stem cell transplantation (CB-RERT) which aspires for regeneration. Therefore, an understanding of the concept, term, difficulties and differences in current protocols is important for the clinician. However, rather than being discouraged that ideal regeneration has not been achieved to date, repair can be an acceptable outcome in clinical regenerative endodontics as it has also been accepted in medicine. Repair should also be considered in the context that resolution of the clinical signs/symptoms of pulp necrosis/apical periodontitis is generally reliably obtained in clinical regenerative endodontics.

The Tennessee study: factors affecting treatment outcome and healing time following nonsurgical root canal treatment.

AIM: To determine factors that may influence treatment outcome and healing time following root canal treatment. METHODOLOGY: Root filled and restored teeth by pre-doctoral students were included in this study. Teeth/roots were followed-up regularly, and treatment outcome was evaluated at every follow-up appointment (healed, healing, uncertain or unsatisfactory). Host (age, immune condition, pulp/periapical diagnosis, tooth/root type, location and anatomy) and treatment factors (master apical file size, apical extension, voids and density of root filling) were recorded from patient dental records. Univariate, bivariate and multivariate analyses were performed to determine the impact of the factors on treatment outcomes and healing times. RESULTS: A total of 422 roots from 291 teeth met the inclusion criteria with a mean follow-up period of 2 years. The preoperative pulp condition, procedural errors during treatment, apical extension and density of root fillings significantly affected the treatment outcome. The average time required for a periapical lesion to heal was 11.78 months. The healing time increased in patients with compromised healing, patients older than 40 years, roots with Weine type II root canal systems, root canal systems prepared to a master apical file size <35, and roots with overextended fillings (P < 0.1). CONCLUSION: Multiple host and treatment factors affected the healing time and outcome of root canal treatment. Follow-up protocols should consider these factors before concluding the treatment outcome: patient's age, immune condition, as well as roots with overextended fillings, root canal systems with smaller apical preparations (size <35) or roots with complex canal systems. Intervention may be recommended if the treatment quality was inadequate or if patients became symptomatic.

Regeneration of the dentine-pulp complex with revitalization/revascularization therapy: challenges and hopes.

The concept of regenerative endodontics has gained much attention in clinical endodontics in the past decade. One aspect of this discipline is the application of revitalization/revascularization therapies for infected and/or necrotic immature pulps in permanent teeth. Following the publication of a case report (Iwaya et al. ), investigators have been rigorously examining the types of tissues formed in the canals as well as exploring strategies to regenerate the pulp-dentine complex in revitalized teeth. This review will provide an update on the types of tissues generated in the canals after revitalization/revascularization therapy in both animal and human studies. The understanding of the role of stem cells and microenvironment in the process of wound healing resulting in either regeneration or repair will be thoroughly discussed. Stem cells and microenvironmental cues introduced into the canal during revitalization/revascularization procedures will be examined. In addition, requirement of a sterile microenvironment in the canal and vital tissue generation in revitalization/revascularization therapy will be emphasized. The challenges that we face and the hopes that we have in revitalization/revascularization therapy for regenerative endodontics will be presented.

Neovascularization by DPSC-ECs in a Tube Model for Pulp Regeneration Study.

The process of neovascularization during cell-based pulp regeneration is difficult to study. Here we developed a tube model that simulates root canal space and allows direct visualization of the vascularization process in vitro. Endothelial-like cells (ECs) derived from guiding human dental pulp stem cells (DPSCs) into expressing endothelial cell markers CD144, vWF, VEGFR1, and VEGFR2 were used. Human microvascular endothelial cells (hMVECs) were used as a positive control. DPSC-ECs formed tubules on Matrigel similar to hMVECs. Cells were mixed in fibrinogen/thrombin or mouse blood and seeded into wells of 96-well plates or injected into a tapered plastic tube (14 mm in length and 1 or 2 mm diameter of the apex opening) with the larger end sealed with MTA to simulate root canal space. Cells/gels in wells or tubes were incubated for various times in vitro and observed under the microscope for morphological changes. Samples were then fixed and processed for histological analysis to determine vessel formation. Vessel-like networks were observed in culture from 1 to 3 d after cell seeding. Cells/gels in 96-well plates were maintained up to 25 d. Histologically, both hMVECs and DPSC-ECs in 96-well plates or tubes showed intracellular vacuole formation. Some cells showed merged large vacuoles indicating the lumenization. Tubular structures were also observed resembling blood vessels. Cells appeared healthy throughout the tube except some samples (1 mm apical diameter) in the coronal third. Histological analysis also showed pulp-like soft tissue throughout the tube samples with vascular-like structures. hMVECs formed larger vascular lumen size than DPSC-ECs while the latter tended to have more lumen and tubular structure counts. We conclude that DPSC-ECs can form vascular structures and sustained in the 3-dimensional fibrin gel system in vitro. The tube model appears to be a proper and simple system simulating the root canal space for vascular formation and pulp regeneration studies.

Regeneration of dental pulp tissue in immature teeth with apical periodontitis using platelet-rich plasma and dental pulp cells.

AIM: To investigate the new tissues growing into the pulp space of immature dog teeth that were infected, disinfected and filled with blood clot (BC), dental pulp cells (DPCs), platelet-rich plasma (PRP) or a combination of DPCs and PRP in immature dog teeth with apical periodontitis. METHODOLOGY: Fifty-six immature roots from mandibular premolars of four beagles were divided into four experimental groups (n = 40) and two control groups. After the induction of apical periodontitis, the root canals of experimental groups were disinfected with NaOCl irrigation and a tri-antibiotic paste medication. The canals were then filled with different materials according to the experimental group: BC group, DPCs group, PRP group or DPCs + PRP group. Access cavities were sealed with MTA and composite. Radiographs were taken after 90 days, and the jaws including the teeth were processed for histologic analysis. The data were statistically analysed using chi-square evaluation and Student's t-test. RESULTS: Radiographic analyses demonstrated no significant difference between experimental groups in periradicular bone healing (P > 0.05), whilst those groups that used DPCs produced a significantly greater root thickening (P < 0.01). The histologic evaluation showed that the groups with PRP formed more tissues in the canals (P = 0.01). The groups with DPCs had substantially more mineralized tissue formation in the canal than those without DPCs, especially in the apical third. In DPCs + PRP group, bone-like tissue grew into the canal space from the periapical tissue. CONCLUSIONS: A combination of DPCs + PRP increased vital tissue regeneration within the root canals of immature teeth associated with apical periodontitis.

[Plasmids carried by carbapenems-resistant Klebsiella pneumoniae in burn patients and its correlation with strain transmission].

Objective: To explore the carrier status of carbapenems-resistant Klebsiella pneumoniae (CRKP) plasmids in burn patients and analyze the correlation of these plasmids with the transmission of CRKP. Methods: A retrospective observational study was conducted. A total of 26 CRKP strains, which were isolated from the clinic-related samples of 22 burn patients (with 20 males and 2 females, aged (42±16) years) admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January to December 2017, were collected and individually numbered. The plasmids of the strains were extracted by alkali lysis. After determination of the plasmid concentration by a nucleic acid concentration detector, the agarose gel electrophoresis was used to visualize the bands, and rough plasmids typing was performed. The plasmid of the smallest numbered CRKP in each plasmid type was transformed into competent Escherichia coli (E. coli) strain Top10 (hereinafter referred to as TOP10 strain). The growth of each transformed strains and a Top10 strain cultivated in ampicillin containing Luria-Bertani (LB) agar medium overnight was observed, and the proportion of successful transformation was calculated. The plasmids from the smallest numbered plasmid carrying CRKP strain of successfully transformed Top10 strains (hereinafter referred to as the smallest successfully transformed strain) and correspondingly numbered CRKP were extracted, and then, the agarose gel electrophoresis was used to visualize the bands. Aforementioned successfully transformed strains and a TOP10 strain were used for the antimicrobial susceptibility testing with 17 antibiotics commonly used in clinic. The plasmid from the smallest successfully transformed strain was sequenced using the next-generation sequencing technology. Bioinformatics analyses such as protein-coding gene prediction and protein sequence alignment were performed successively. The sequence was subsequently named pKP03-NDM1 according to the carrying of drug resistance gene. According to the whole genome sequence of the plasmid carried by the smallest successfully transformed strain, the polymerase chain reaction, agarose gel electrophoresis, and gene sequencing were used to detect the New Delhi metallo-beta lactamase-1 (blaNDM-1) of plasmids in the remaining 25 strains of CRKP. The ST typing in multilocus sequence typing of 26 strains of CRKP was analyzed based on the literature. Results: Plasmids were successfully extracted from 26 CRKP, with mass concentrations ranging from 19.3 to 189.8 ng/µL. Each of the 26 CRKP carrying plasmids showed at least one band longer than 2 500 bp in the agarose gel electrophoresis, which were roughly divided into 6 patterns of A, B, C, D, E, and F. After overnight cultivation, no growth of strains was observed in LB agar medium containing ampicillin inoculated with the TOP10 strain or TOP10 strains transformed by the plasmid of CRKP patterning A, B, D, or E. In contrast, TOP10 strains transformed by the pattern C plasmid from NO.3 CRKP and the pattern F plasmid from NO.15 CRKP resulted in numerous colony growths, and those transformed strains were named as TOP10-pKP03 and TOP10-pKP15, respectively. The proportion of successful transformation was 1/3. The plasmid carried by TOP10-pKP03 showed a single band in the agarose gel electrophoresis, which was the same size as the largest band of the plasmid from NO.3 CRKP. The TOP10 strain was sensitive to the 17 antibiotics commonly used in clinic. TOP10-pKP03 and TOP10-pKP15 were resistant to penicillins, cephalosporins, and carbapenems but remained sensitive to monocyclic ß-lactam, aminoglycosides, quinolones and tigecycline. The full length of the plasmid carried by TOP10-pKP03 was 41 190 bp. In addition to blaNDM-1, this plasmid carried bleMBL, T4SS, bleomycin resistance gene, conjugation transfer elements, and relaxase, etc. The plasmid showed 99% nucleotide identity similarity and the same length to the plasmid pJN24NDM1 extracted from an E. coli isolate JN24. Totally 16 (61.5%) CRKP were confirmed to carrying blaNDM-1 gene, among the ST typing of the 16 strains, 11 strains were ST11, while ST215, ST260, ST395, ST2230, and new ST had 1 strain each. Among the ST typing of 10 blaNDM-1-negative CRKP, 8 strains were ST11, while ST395 and ST2230 had 1 strain each. Conclusions: A blaNDM-1 gene carrying plasmid pKP03-NDM1 was extracted and sequenced from CRKP isolated from burn patients, with a high plasmid carrying rate. Meanwhile, this plasmid may mediate inter-CRKP and CRKP-E. coli horizontal transfer of blaNDM-1, leading to transmission of antimicrobial resistance.

[Clinical application effects of two longitudes three transverses method in perforator location of thoracodorsal artery perforator flap and deep wound repair].

Objective: To explore the clinical application value of two longitudes three transverses method in the location of the perforator of thoracodorsal artery perforator and deep wound repair. Methods: The retrospectively observational study was conducted. From December 2018 to June 2020, 17 patients with deep wounds who were admitted to the Affiliated Hospital of Zunyi Medical University met the inclusion criteria and were included in this study, including 7 males and 10 females, aged 12 to 72 years. The wound areas of patients after debridement were 7 cm×3 cm to 11 cm×7 cm. Two longitudinal lines were located through the midpoint of the armpit, the posterior superior iliac spine, and the protruding point of the sacroiliac joint, and three transverse lines were located 5, 10, and 15 cm below the midpoint of the armpit between the two longitudinal lines, i.e. two longitudes three transverses method, resulting in two trapezoidal areas. And then the thoracodorsal artery perforators in two trapezoidal areas were explored by the portable Doppler blood flow detector. On this account, a single or lobulated free thoracodorsal artery perforator flap or flap that carrying partial latissimus dorsi muscle, with an area of 7 cm×4 cm to 12 cm×8 cm was designed and harvested to repair the wound. The donor sites were all closed by suturing directly. The number and location of thoracodorsal artery perforators, and the distance from the position where the first perforator (the perforator closest to the axillary apex) exits the muscle to the lateral border of the latissimus dorsi in preoperative localization and intraoperative exploration, the diameter of thoracodorsal artery perforator measured during operation, and the flap types were recorded. The survivals of flaps and appearances of donor sites were followed up. Results: The number and location of thoracodorsal artery perforators located before operation in each patient were consistent with the results of intraoperative exploration. A total of 42 perforators were found in two trapezoidal areas, with 2 or 3 perforators each patient. The perforators were all located in two trapezoid areas, and a stable perforator (the first perforator) was located and detected in the first trapezoidal area. There were averagely 1.47 perforators in the second trapezoidal area. The position where the first perforator exits the muscle was 2.1-3.1 cm away from the lateral border of the latissimus dorsi. The diameters of thoracodorsal artery perforators were 0.4-0.6 mm. In this group, 12 cases were repaired with single thoracodorsal artery perforator flap, 3 cases with lobulated thoracodorsal artery perforator flap, and 2 cases with thoracodorsal artery perforator flap carrying partial latissimus dorsi muscle. The patients were followed up for 6 to 16 months. All the 17 flaps survived with good elasticity, blood circulation, and soft texture. Only linear scar was left in the donor area. Conclusions: The two longitudes three transverses method is helpful to locate the perforator of thoracodorsal artery perforator flap. The method is simple and reliable. The thoracodorsal artery perforator flap designed and harvested based on this method has good clinical effects in repairing deep wound, with minimal donor site damage.

[Research advances on the development and application of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein system].

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) protein system, as an emerging gene editing system, can be divided into class 1 and class 2 systems according to the number of Cas protein. The CRISPR/Cas9 in class 2 system can cleave target nucleic acid only with the help of Cas9 protein and single-stranded guide RNA, which is currently the most widely used CRISPR/Cas system. In addition to gene editing in the treatment of genetic diseases, a variety of CRISPR/Cas system derived technologies have vast application prospect in the fields of disease-related gene screening, gene expression regulation, and rapid detection, prevention, and control of pathogens. This article summarizes the discovery process of CRISPR/Cas system and applications of several major CRISPR/Cas derived technologies, aiming to provide a reference for researchers in the field of life science.

Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases.

OBJECTIVE: Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients. MATERIALS AND METHODS: In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) > OR = 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32-72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters. RESULTS: Clinical examination indicated that transplantationof PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs. CONCLUSIONS: This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.

Expression of Normal or Mutated X-Linked BCOR Transcripts in OFCD iPSCs.

Reprogramming diseased cells with mutated genes into induced pluripotent stem cells (iPSCs) can allow studies of disease mechanism and correct the mutation. Oculofaciocardiodental (OFCD) syndrome is a developmental disorder caused by heterozygous mutations in the X-linked BCL-6 corepressor (BCOR) gene. In this present study, we aimed to reprogram stem cells from a tooth apical papilla (SCAP) of a patient with OFCD, termed SCAP-O, into iPSCs. The SCAP-O carry a copy of the BCOR gene having 1 nucleotide deletion in 1 of the alleles, therefore harboring a mixture of cells expressing either normal (SCAP-OBCOR-WT) or mutated (SCAP-OBCOR-mut) BCOR transcripts. We subcloned SCAP-O and separated SCAP-OBCOR-WT and SCAP-OBCOR-mut as verified by sequencing. The selected subclone SCAP-OBCOR-mut expressed only the mutated BCOR transcripts and remained in such condition after multiple passages. We reprogrammed SCAP-O and subclone SCAP-OBCOR-mut into transgene-free iPSCs using an excisable lentiviral vector system (hSTEMCCA-loxP) carrying 4 reprogramming factors in a single cassette, followed by removal of transgenes via Cre-mediated excision. We found that after reprogramming SCAP-O or subclone SCAP-OBCOR-mut into iPSCs, some of the iPSC clones expressed either solely the normal BCOR-WT or BCOR-mut transcripts, while other clones expressed both BCOR-WT and BCOR-mut transcripts. This is our first step toward establishing OFCD study models by generating isogenic control BCOR-WT iPSCs versus BCOR-mut iPSCs.

The neutrophil to lymphocyte ratio as a novel predictor of asthma and its exacerbation: a systematic review and meta-analysis.

OBJECTIVE: It is widely known that the main white blood cell populations, and neutrophil to lymphocyte ratio (NLR), are involved in systemic inflammation. The usefulness of NLR measurements has been reported in patients with asthma. We performed a systematic review and meta-analysis of studies to investigate the relationship between the NLR and asthma and its exacerbations. MATERIALS AND METHODS: We systematically searched PubMed and Embase databases for studies (published between Jan 1, 1950 and Jan 2, 2020; no language restrictions) comparing the NLR values in patients with stable asthma or asthma exacerbations to healthy controls. We assessed pooled data by use of a random-effects model. RESULTS: Of 260 identified studies, 6 were eligible and were included in our analysis (N = 2418 participants). Compared with 439 healthy controls, 743 stable asthma patients in four studies showed significantly greater NLR values (standardized mean difference, SMD, 0.567, 95% CI 0.212-0.922; p = 0.002). Furthermore, compared with 1063 stable asthma patients, 402 asthma exacerbation patients yielded significantly greater NLR values (random effects SMD 1.335, 95% CI 0.429-2.241; p < 0.001). CONCLUSIONS: Our meta-analysis showed that the NLR values are a reasonable and easy-to-use marker for asthma and its exacerbations. Further studies, with larger sample sizes and more phenotypes, are required to establish its use as a predictive parameter in asthma.

[Influence of human amniotic mesenchymal stem cells on macrophage phenotypes and inflammatory factors in full-thickness skin wounds of mice].

Objective: To explore the influence of human amniotic mesenchymal stem cells (hAMSCs) on the in vivo and in vitro regulation of macrophage phenotypes and inflammatory factors associated with wound healing of full-thickness skin wounds in mice. Methods: Fresh amniotic membrane discarded from full-term delivery by 5 healthy pregnant women in the Department of Obstetrics and Gynecology of the Affiliated Hospital of Zunyi Medical University was used for the isolation and culture of hAMSCs by enzyme digestion method. The third passage of cells was used for identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of hAMSCs surface markers. Ten C57BL/6 mice (all male, aged 6 to 8 weeks, the same gender and age below) were selected for extracting mouse peritoneal macrophages by intraperitoneal lavage, and M1-type macrophages were induced by Dulbecco's modified eagle medium (DMEM) medium containing interferon-γ. The M1-type macrophages were divided into hAMSCs+ macrophage group and macrophage alone group. Then 1×10(4) hAMSCs/per well of fourth passage were added to macrophage in hAMSCs+ macrophage group and cultured in 2 mL DMEM medium for routine culture. In macrophage alone group, each well was only added with 2 mL DMEM medium for routine culture. On day 1 and 7 in culture, the content of interleukin-12 (IL-12), arginase 1, and IL-10 in the cell culture supernatant of the 2 groups were detected by enzyme-linked immunosorbent assay with sample number of 6/per group. (2) Full-thickness skin wound model was reproduced in the back of 56 C57BL/6 mice, which were divided into hAMSCs group and phosphate buffer solution (PBS) group using the random number table, with 28 mice in each group. Mice in hAMSCs group were subcutaneously injected with 100 µL of cell suspension containing 1×10(7) hAMSCs per mL in PBS suspension along the wound edge. While mice in PBS group were only subcutaneously injected with 100 µL PBS along the wound edge. On post injection day (PID) 1, 3, 7, and 14, 7 mice in the two groups were sacrificed respectively. Histopathological observation was performed with hematoxylin-eosin staining. The expressions of macrophage surface markers [CD68 and inducible nitric oxide synthase (iNOS) double positive cells and CD68 and arginase 1 double positive] in the wounds were detected by immunofluorescent staining. The mRNA expressions of IL-10, macrophage inflammatory protein 1α (MIP-1α), and MIP-2 in the wounds were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results: (1) On day 1 in culture, the content of IL-12 and arginase 1 in the cell culture supernatant of the two groups were similar (t=0.448, 0.536, P>0.05), and the content of IL-10 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=14.722, P<0.01). On day 7 in culture, the content of IL-12 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=13.226, P<0.01), and the content of arginase 1 and IL-10 was significantly higher than that in macrophage alone group (t=30.172, 31.406, P<0.01). (2) On PID 1, a large number of inflammatory cells infiltration were observed in the skin wounds of both groups. On PID 3, the inflammatory cells infiltration in the skin wounds increased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 7, the inflammatory cells infiltration in the wounds decreased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 14, no obvious inflammatory cells infiltration was observed in the wounds in the two groups. (3) On PID 1 and 14, the percentages of CD68 and iNOS double positive cells and CD68 and arginase 1 double positive cells in the wounds were similar in the two groups (t(1 d)=0.134, 0.693, t(14 d)=1.146, 2.585, P>0.05). On PID 3 and 7, the percentages of CD68 and iNOS double positive cells in the wounds in hAMSCs group were significantly lower than those of PBS group (t=6.396, 4.787, P<0.01), while the percentages of CD68 and arginase 1 double positive cells were significantly higher than those of PBS group (t=3.928, 4.473, P<0.01). (4) On PID 1, the mRNA expressions of IL-10 in the wounds of mice in the two groups were similar (t=2.005, P>0.05). On PID 3, 7, and 14, the mRNA expressions of IL-10 in the wounds of mice in hAMSCs group were significantly higher than those of PBS group (t=7.758, 124.355, 80.823, P<0.01). On PID 1, 3, 7, and 14, the mRNA expressions of MIP-1α and MIP-2 in the wounds of mice in hAMSCs group (0.341±0.212, 0.648±0.004, 0.611±0.106, 0.763±0.049, 1.377±0.099, 1.841±0.042, 1.181±0.035, 0.553±0.028) were significantly lower than those of PBS group (3.853±0.035, 6.914±0.163, 3.648±0.113, 2.250±0.046, 11.119±0.495, 8.634±0.092, 5.722±0.021, 4.862±0.036, t=43.198, 101.904, 51.845, 58.231, 51.074, 177.501, 291.752, 251.614, P<0.01). Conclusions: hAMSCs demonstrates biological effects of promoting the transformation of M1-type macrophages into M2-type macrophages in full-thickness skin wounds of mice. They can up-regulate the expression of anti-inflammatory and anti-fibrotic factor IL-10, and down-regulate the expression of important inflammation mediated factors MIP-1α and MIP-2.

[Clinical effects of modified fascia flap from cutaneous branch of dorsal metacarpal artery in repairing the wound at the proximal and middle finger segments].

Objective: To investigate the clinical effects of modified fascia flap from cutaneous branch of dorsal metacarpal artery in repairing the wound at the proximal and middle finger segments. Methods: From January 2017 to September 2018, 12 patients with wounds at the proximal and middle finger segments were admitted to the Affiliated Hospital of Zunyi Medical University, including 8 males and 4 females, aged 35-70 years. The areas of wounds ranged from 3.4 cm×2.4 cm to 6.5 cm×4.0 cm. The modified fascia flaps from cutaneous branch of dorsal metacarpal artery were resected to repair the wounds, with the size ranging from 3.5 cm×2.5 cm to 6.7 cm×4.1 cm. The flap donor sites of 5 patients were repaired with direct intermittent suture, the flap donor sites of 4 patients were repaired with full-thickness skin grafts from ipsilateral medial forearm, and the flap donor sites of 3 patients were repaired with wrist pedicled flaps. The survival of the flaps was recorded. Healing of donor site and recipient site was followed. The hand functions were evaluated with trial standard for the evaluation of the functions of the upper limbs of the Hand Surgery Society of the Chinese Medical Association. Results: All the flaps survived in 12 cases. During 3 to 12 months of follow-up, the flaps recovered satisfactorily in texture and shape. The donor sites of 11 patients were healed, and the skin graft edge area was partially necrotic in the other patient but healed later after dressing change. The distances of two-point discrimination of the patients ranged from 5.6 to 9.0 mm. Hand functions were evaluated as excellent in 5 cases, good in 4 cases, and fair in 3 cases. Conclusions: Modified fascia flap from cutaneous branch of dorsal metacarpal artery for repairing the wounds at the proximal and middle finger segments has reliable blood supply. The operation is simple and safe with short course of treatment, which is worthy of clinical promotion.

Apexification: the beginning of its end.

Apexification is a procedure for treating and preserving immature permanent teeth that have lost pulp vitality. It contrasts apexogenesis in terms of its outcome in that apical maturation and normal root thickness cannot be obtained. Apexification has been a routine practice for such teeth for many decades, and despite a literature replete with discussion, including recent artificial barrier methods with mineral trioxide aggregate, ultimately there has been no major breakthrough to improve this treatment. Recently, two new clinical concepts have emerged. One involves a revitalization approach to achieve tissue generation and regeneration. In this method, new living tissue is expected to form in the cleaned canal space, allowing continued root development in terms of both length and thickness. The other is the active pursuit of pulp/dentine regeneration via tissue engineering technology to implant or re-grow pulps. Although the technology is still at its infancy, it has the potential to benefit immature pulpless teeth by allowing continued growth and maturation. With this understanding, it may be predicted that apexification will become less needed in years to come. This study will overview the recent concept of pulp revitalization in the treatment of immature teeth with nonvital pulps and the emerging research on pulp tissue engineering and regeneration.

[Progress in the treatment of chronic wound and discussion on the integrated surgical wound treatment mode].

With the change of disease spectrum and the progress in the aging of society, chronic wound has gradually become one of the major diseases that threaten human health, and also one of the major economic burdens of family and society. According to the different etiology, the pathogenesis of chronic wound is different, including both systemic factors and local factors. The treatment of chronic wound is a multi-disciplinary integrated treatment process, including internal medicine treatment, surgical treatment, vascular interventional therapy, platelet-rich plasma treatment, and biological therapy, etc. Each treatment regimen has its own indications and pros and cons. To make a treatment regimen, a combination of a variety of options should be chosen according to the patient's wound conditions. The traditional chronic wound treatment mode is multi-disciplinary team (MDT) treatment mode, which requires the participation of surgeons from multiple departments such as intervention department, plastic surgery department, orthopedics department, etc., and it is also the mainstream mode for treating chronic wound in western countries. According to the domestic medical situation and the experience of our department, we put forward the integrated surgical wound treatment (ISWT) mode, that is to integrate multiple surgical techniques of wound treatment. Compared with the traditional MDT treatment mode, to apply the ISWT mode can make a more reasonable treatment plan, improve the efficiency of diagnosis and treatment, shorten the hospitalization period, and improve the diagnosis and treatment ability of the team. With the increasing incidence of chronic wound, the ISWT mode needs to be further explored and improved, and the team needs more specialized experts to join in.

[Review of development of Department of Burns and Plastic Surgery in the Affiliated Hospital of Zunyi Medical College].

In the 60th anniversary of Chinese burn medicine, I am honored to review the development of Department of Burns and Plastic Surgery in the Affiliated Hospital of Zunyi Medical College. The Affiliated Hospital of Dalian Medical college was relocated to Zunyi in 1969 to support the development of southwestern China and renamed Affiliated Hospital of Zunyi Medical College. Only a few medical workers stayed in Zunyi when the State Council decided to reestablish Dalian Medical University in 1978. In the last 30 years, our department made great progress in the field of burns treatment with Chinese and Western medicine and complex wounds repair with flap, especially with perforator flap. We also took the lead to achieve the integrated treatment model, including peripheral vascular intervention, autogenous adipose cells/adipose-derived stem cells transplantation, platelet-rich plasma/platelet-rich fibrin, flap grafting, vacuum sealing drainage, Ilizarov technology, and functional active dressing for the treatment of chronic and ischemic wounds. Our department has become one of the national key clinical subject with certain influence from low ebb.

Infection of human intestinal epithelial cells with invasive bacteria upregulates apical intercellular adhesion molecule-1 (ICAM)-1) expression and neutrophil adhesion.

The acute host response to gastrointestinal infection with invasive bacteria is characterized by an accumulation of neutrophils in the lamina propria, and neutrophil transmigration to the luminal side of the crypts. Intestinal epithelial cells play an important role in the recruitment of inflammatory cells to the site of infection through the secretion of chemokines. However, little is known regarding the expression, by epithelial cells, of molecules that are involved in interactions between the epithelium and neutrophils following bacterial invasion. We report herein that expression of ICAM-1 on human colon epithelial cell lines, and on human enterocytes in an in vivo model system, is upregulated following infection with invasive bacteria. Increased ICAM-1 expression in the early period (4-9 h) after infection appeared to result mainly from a direct interaction between invaded bacteria and host epithelial cells since it co-localized to cells invaded by bacteria, and the release of soluble factors by epithelial cells played only a minor role in mediating increased ICAM-1 expression. Furthermore, ICAM-1 was expressed on the apical side of polarized intestinal epithelial cells, and increased expression was accompanied by increased neutrophil adhesion to these cells. ICAM-1 expression by intestinal epithelial cells following infection with invasive bacteria may function to maintain neutrophils that have transmigrated through the epithelium in close contact with the intestinal epithelium, thereby reducing further invasion of the mucosa by invading pathogens.

Splicing mutations of the p53 gene in human hepatocellular carcinoma.

Point mutations in exons of the tumor suppressor p53 gene occur frequently in many human tumors including hepatocellular carcinoma and are extensively studied. However, intronic point mutations are rare and are totally unknown for hepatocellular carcinoma. By reverse transcription and polymerase chain reaction amplification of p53 RNA from hepatocellular carcinoma tissues of 45 Taiwanese patients, we found amplified complementary DNA fragments of abnormal size in 4 (9%) tumor samples. Sequence analysis of these complementary DNA products revealed aberrant retention of intron 7 in one sample, insertion of 49 base pairs of the 3' end of intron 6 in 2 samples, and deletion of exon 4 in the other sample. Direct sequencing of their genomic DNA revealed relevant point mutations at consensus sequence at either the 5' or 3' splice site of intron 7, 6, 6, and 3, respectively. The splicing mutations produced p53 mutants with truncation of COOH-terminus that are identical to those found in lung cancers. Three of the 4 patients with splicing mutations were younger and had huge tumors. The results suggest a possible role of these p53 mutants in the development of human cancers.

Mutation of p53 gene in hepatocellular carcinoma in Taiwan.

To elucidate the role of p53 mutation in hepatocarcinogenesis in Taiwan, a hepatitis B viral infection hyperendemic area, exons 5 to 8 of the p53 gene in the tumor tissue of 61 hepatocellular carcinomas were amplified and sequenced. A total of 20 cases (32.8%) were found to have mutations; 36.6% (15 of 41) for the hepatitis B surface antigen positive group and 25.0% (5 of 20) for the hepatitis B surface antigen negative group. The corresponding normal liver showed no mutation. The mutation is widely distributed throughout exons 5 to 8. Only 4 cases (6.6%), all positive for hepatitis B surface antigen, had a specific hot spot mutation at codon 249 with G to T transversion. Our results show that scattered point mutations in p53 are not uncommon in hepatocellular carcinoma samples from Taiwan and may be important in the development of this cancer. However, the aflatoxin related specific mutation seems much less related to the genesis of hepatocellular carcinoma in Taiwan.

[Phage therapy for bacterial infection of burn].

With the long-term and widespread use of antibiotics, drug resistance of bacteria has become a major problem in the treatment of burn infection. For treating multidrug resistant bacteria, phage therapy has become the focus of attention. Development of phage therapy to fill the blank of this field in China is extremely urgent.