Humanized V(D)J-rearranging and TdT-expressing mouse vaccine models with physiological HIV-1 broadly neutralizing antibody precursors.

Antibody heavy chain (HC) and light chain (LC) variable region exons are assembled by V(D)J recombination. V(D)J junctional regions encode complementarity-determining-region 3 (CDR3), an antigen-contact region immensely diversified through nontemplated nucleotide additions ("N-regions") by terminal deoxynucleotidyl transferase (TdT). HIV-1 vaccine strategies seek to elicit human HIV-1 broadly neutralizing antibodies (bnAbs), such as the potent CD4-binding site VRC01-class bnAbs. Mice with primary B cells that express receptors (BCRs) representing bnAb precursors are used as vaccination models. VRC01-class bnAbs uniformly use human HC VH1-2 and commonly use human LCs Vκ3-20 or Vκ1-33 associated with an exceptionally short 5-amino-acid (5-aa) CDR3. Prior VRC01-class models had nonphysiological precursor levels and/or limited precursor diversity. Here, we describe VRC01-class rearranging mice that generate more physiological primary VRC01-class BCR repertoires via rearrangement of VH1-2, as well as Vκ1-33 and/or Vκ3-20 in association with diverse CDR3s. Human-like TdT expression in mouse precursor B cells increased LC CDR3 length and diversity and also promoted the generation of shorter LC CDR3s via N-region suppression of dominant microhomology-mediated Vκ-to-Jκ joins. Priming immunization with eOD-GT8 60mer, which strongly engages VRC01 precursors, induced robust VRC01-class germinal center B cell responses. Vκ3-20-based responses were enhanced by N-region addition, which generates Vκ3-20-to-Jκ junctional sequence combinations that encode VRC01-class 5-aa CDR3s with a critical E residue. VRC01-class-rearranging models should facilitate further evaluation of VRC01-class prime and boost immunogens. These new VRC01-class mouse models establish a prototype for the generation of vaccine-testing mouse models for other HIV-1 bnAb lineages that employ different HC or LC Vs.

TrieDedup: a fast trie-based deduplication algorithm to handle ambiguous bases in high-throughput sequencing.

BACKGROUND: High-throughput sequencing is a powerful tool that is extensively applied in biological studies. However, sequencers may produce low-quality bases, leading to ambiguous bases, 'N's. PCR duplicates introduced in library preparation are conventionally removed in genomics studies, and several deduplication tools have been developed for this purpose. Two identical reads may appear different due to ambiguous bases and the existing tools cannot address 'N's correctly or efficiently. RESULTS: Here we proposed and implemented TrieDedup, which uses the trie (prefix tree) data structure to compare and store sequences. TrieDedup can handle ambiguous base 'N's, and efficiently deduplicate at the level of raw sequences. We also reduced its memory usage by approximately 20% by implementing restrictedDict in Python. We benchmarked the performance of the algorithm and showed that TrieDedup can deduplicate reads up to 270-fold faster than pairwise comparison at a cost of 32-fold higher memory usage. CONCLUSIONS: The TrieDedup algorithm may facilitate PCR deduplication, barcode or UMI assignment, and repertoire diversity analysis of large-scale high-throughput sequencing datasets with its ultra-fast algorithm that can account for ambiguous bases due to sequencing errors.

Disulfiram Improves Fat Graft Retention by Modulating Macrophage Polarization With Inhibition of NLRP3 Inflammasome-Mediated Pyroptosis.

BACKGROUND: Macrophage-mediated inflammatory response in the early post-grafting period restricts fat graft retention. Pyroptosis is a novel type of programmed cell death that extensively participates in inflammatory pathologies. OBJECTIVES: This study sought to determine whether macrophage pyroptosis was activated during the inflammatory phase after fat grafting and to investigate the efficacy of a pyroptosis inhibitor, disulfiram (DSF), in fat graft retention. METHODS: We established a C57BL/6 mice fat grafting model and then analyzed macrophage pyroptosis. DSF (50 mg/kg, every other day) was intraperitoneally injected starting 1 hour before fat grafting and continued for 14 days. An in vitro co-culture system was established in which mouse RAW264.7 macrophages were co-cultured with apoptotic adipocytes to further validate the findings of the in vivo studies and to explore the underlying mechanisms. RESULTS: Here we reported that macrophage pyroptosis was activated in both fat grafts and in vitro co-culture models. DSF was found to be a potent pyroptosis inhibitor, promoting M2 macrophage polarization. In addition, DSF was demonstrated to enhance vascularization and graft retention. CONCLUSIONS: Our results suggested that pyroptosis plays a crucial role in the inflammatory cascade within fat grafts. DSF, being a clinically available drug, could be translated into a clinically effective drug for improving fat graft survival by inhibiting macrophage pyroptosis, therefore inducing M2 macrophage polarization and promoting neovascularization.

Application of 3-Dimensional Technology for Evaluating Muscular Type and Muscle-Fat Pad Mixed-Type Nasolabial Folds With Botulinum Toxin-A Treatment.

BACKGROUND: Botulinum toxin-A (BTX-A) is used in the treatment of nasolabial folds (NLFs). However, lighting and clinician subjectivity play a major role in evaluating the efficacy of this treatment. OBJECTIVES: By applying 3-dimensional (3D) technology, this study aimed to quantitatively evaluate the effects of BTX-A injection on muscular (M) and muscle-fat pad mixed-type (MF) NLFs. METHODS: BTX-A was injected into bilateral marked points on the NLFs, where the levator labii alaeque nasi, zygomaticus minor, and zygomaticus major pull the skin to form the NLF (2 U at each injection site). Pretreatment and posttreatment 3D facial images were captured with static and laughing expressions. The curvature, width, depth, and lateral fat volume of the NLFs were measured to compare the therapeutic efficacy for type M and MF NLFs. RESULTS: Thirty-nine patients with type M and 37 with type MF NLFs completed the follow-up data. In these patients, the curvature, width, and depth of the NLF showed a significant reduction at 1 month and gradually recovered at 3 and 6 months after treatment, with more significant improvement when laughing than when static. Variations compared to the pretreatment values of type MF were greater than those of type M at each time point. The lateral fat volume of the type MF NLF was significantly reduced (P < .05). CONCLUSIONS: 3D technology can quantitatively evaluate the effects BTX-A injection for treating type M and type MF NLFs. BTX-A is more effective on type MF than on type M NLFs.

The Retention-Rate Improvement of Stromal Vascular Fraction Gel in Prefrontal Filling With Botulinum Toxin-A Injection: A Retrospective Analysis.

BACKGROUND: As a derivative of adipose tissues, stromal vascular fraction gel has been widely utilized in facial soft tissue filling, but it still does not achieve the expected effect in forehead filling. The reason may be related to the corrugator muscles movements. OBJECTIVES: The authors aimed to evaluate the effect of botulinum toxin-A (BTX-A) on the retention rate of stromal vascular fraction gel by limiting the corrugator muscles movements and to provide a theoretical basis that short-term inhibition of movement in the affected area could improve the effects of the fat graft. METHODS: From January 2019 to June 2021, patients with stromal vascular fraction gel facial filling (including frontal and temporal parts) were selected. According to whether or not BTX-A treatment was received, patients were divided into injected and the noninjected groups. A questionnaire and the Global Aesthetic Improvement Scale (GAIS) were administered to evaluate 2-dimensional photos. The retention rate and curvature were calculated with 3-dimensional images utilizing Artec Studio 13 Professional and MATLAB software. RESULTS: The graft retention, forehead curvature, and GAIS scores were all higher in the injected group than the noninjected group (P < .01). On the questionnaire, the injected group also showed more satisfaction with the treatment effect and were more willing to recommend the treatment to their friends. CONCLUSIONS: BTX-A injection can improve the retention rate of prefrontal stromal vascular fraction gel filling, with higher patient satisfaction and better postoperative effects.

Regulation of Multiple Resonance Delayed Fluorescence via Through-Space Charge Transfer Excited State towards High-Efficiency and Stable Narrowband Electroluminescence.

B- and N-embedded multiple resonance (MR) type thermally activated delayed fluorescence (TADF) emitters usually suffer from slow reverse intersystem crossing (RISC) process and aggregation-caused emission quenching. Here, we report the design of a sandwich structure by placing the B-N MR core between two electron-donating moieties, inducing through-space charge transfer (TSCT) states. The proper adjusting of the energy levels brings about a 10-fold higher RISC rate in comparison with the parent B-N molecule. In the meantime, a high photoluminescence quantum yield of 91 % and a good color purity were maintained. Organic light-emitting diodes based on the new MR emitter achieved a maximum external quantum efficiency of 31.7 % and small roll-offs at high brightness. High device efficiencies were also obtained for a wide range of doping concentrations of up to 20 wt % thanks to the steric shielding of the B-N core. A good operational stability with LT95 of 85.2 h has also been revealed. The dual steric and electronic effects resulting from the introduction of a TSCT state offer an effective molecular design to address the critical challenges of MR-TADF emitters.

The lncRNA Hand2os1/Uph locus orchestrates heart development through regulation of precise expression of Hand2.

Exploration and dissection of potential actions and effects of long noncoding RNA (lncRNA) in animals remain challenging. Here, using multiple knockout mouse models and single cell RNA sequencing, we demonstrate that the divergent lncRNA Hand2os1/Uph has a key complex modulatory effect on the expression of its neighboring gene HAND2 and subsequently on heart development and function. Short deletion of the Hand2os1 promoter in mouse diminishes Hand2os1 transcription to ∼8-32%, but fails to affect HAND2 expression and yields no discernable heart phenotypes. Interestingly, full-length deletion of Hand2os1 in mouse causes moderate yet prevalent upregulation of HAND2 in hundreds of cardiac cells, leading to profound biological consequences, including dysregulated cardiac gene programs, congenital heart defects and perinatal lethality. We propose that the Hand2os1 locus dampens HAND2 expression to restrain cardiomyocyte proliferation, thereby orchestrating a balanced development of cardiac cell lineages. This study highlights the regulatory complexity of the lncRNA Hand2os1 on HAND2 expression, emphasizing the need for complementary genetic and single cell approaches to delineate the function and primary molecular effects of an lncRNA in animals.

Application of Three-Dimensional Technology in Evaluating the Lower Face Lifting by Regional Platysma Injection with Botulinum Toxin-A.

BACKGROUND: Botulinum toxin-A (BTX-A) injection of regional platysma has been utilized in the lower-part elevation and mandibular contour sculpture. However, the relative research, especially in quantitative assessment appears very spare. Our aim is to investigate the efficacy of three-dimensional (3D) technology as a method for regional platysma injection with BTX-A. MATERIALS AND METHODS: From October 2019 to September 2020, patients with mild or moderate degrees of facial sagging on the lower face were recruited to regional platysma BTX-A injection, and 3D scanning and measurement technology was used to evaluate the difference of curved distances and angels. Patients' improvement was assessed by the global aesthetic improvement scale (GAIS). RESULTS: A total of 57 patients underwent regional platysma BTX-A injection and 32 patients were followed up successfully. Compared with Pre-operative, postoperative facial reference curves distance and cervico-mental angles had statistical differences (p < 0.05). GAIS suggested that the 3D imaging measurement technology could improve satisfaction. CONCLUSION: 3D technology can evaluate the improvement of the lower face with BTX-A. It provides effective measurement methods and raises satisfaction. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effect of Positional Changes on Skin Landmarks in Midface Filling.

BACKGROUND: The design lines for midfacial filling shift upward with a patient's position changes from upright to supine during operation. This will cause the actual filled part to deviate from the target area. OBJECTIVES: This authors aimed to evaluate the effect of positional changes on midfacial landmarks and find the optimal body position for midface filling. METHODS: The process involved the grading and evaluation stages. The midfacial laxity of each sample in the evaluation stage was graded into minimal, moderate, and severe by the system established in the grading stage. Measured through the 3-dimensional images in each grade, the vertical distances from landmarks C, D, and E (representing the region of the tear trough, infraorbital area, and nasolabial fat pad, respectively) to the horizontal line of the inner canthus and depth of nasolabial fold at an angle of 90° were separately compared with those from the other angles (60°, 45°, 30°, and 0°) of the operating table. RESULTS: In the minimal midfacial laxity group, all 3 landmarks significantly moved upward when the angle decreased to 30°. However, landmark E of the moderate and severe and landmark D of the severe midfacial laxity groups both significantly moved upward when the angle decreased to 45°. The depth of the nasolabial fold at a 45° angle was significantly less than that at a 90° angle in the moderate and severe groups. CONCLUSIONS: In midface filling, a patient's body position should be optimally selected according to the midfacial laxity and filling area.

Anatomic Characteristics and Treatment of the Midcheek Groove by Deep Filling.

BACKGROUND: Because the anatomic mechanisms underlying the formation of the midcheek groove are unclear, treatments to date have resulted in unsatisfactory outcomes. OBJECTIVE: This study investigated the anatomical foundation of the midcheek groove and evaluated appropriate treatment methods. MATERIALS AND METHODS: Six cadaver hemifacial specimens were subjected to gross anatomic dissection and 6 to P45 sheet plastination. Based on the anatomic results, the area under the orbicularis oculi muscle (OOM) was selected for deep filling. Patients were evaluated by measuring 3D depth, regrading, and self-assessment. RESULTS: The medial band was observed to be an important structure of the OOM, with the facial projection overlapping the midcheek groove trace. Two of the 6 P45 specimens were found to have compact fibroelastic bundles (CFBs) between the medial band and the dermis. Deep filling of the area under the OOM significantly reduced the depth of each section in all 34 patients (p < .001). Grades 3 and 4 midcheek grooves were downgraded distinctively. Most subjects expressed satisfaction with outcomes. CONCLUSION: Formation of the midcheek groove is associated with the passage of CFBs. Deep filling of the area under the OOM effectively improves the midcheek grooves.

Insight into novel RNA-binding activities via large-scale analysis of lncRNA-bound proteome and IDH1-bound transcriptome.

RNA-binding proteins (RBPs) play pivotal roles in directing RNA fate and function. Yet the current annotation of RBPs is largely limited to proteins carrying known RNA-binding domains. To systematically reveal dynamic RNA-protein interactions, we surveyed the human proteome by a protein array-based approach and identified 671 proteins with RNA-binding activity. Among these proteins, 525 lack annotated RNA-binding domains and are enriched in transcriptional and epigenetic regulators, metabolic enzymes, and small GTPases. Using an improved CLIP (crosslinking and immunoprecipitation) method, we performed genome-wide target profiling of isocitrate dehydrogenase 1 (IDH1), a novel RBP. IDH1 binds to thousands of RNA transcripts with enriched functions in transcription and chromatin regulation, cell cycle and RNA processing. Purified IDH1, but not an oncogenic mutant, binds directly to GA- or AU-rich RNA that are also enriched in IDH1 CLIP targets. Our study provides useful resources of unconventional RBPs and IDH1-bound transcriptome, and convincingly illustrates, for the first time, the in vivo and in vitro RNA targets and binding preferences of IDH1, revealing an unanticipated complexity of RNA regulation in diverse cellular processes.

Long-term oncologic safety of immediate reconstructive surgery in patients with invasive breast cancer: a retrospective matched-cohort study.

OBJECTIVE: Immediate reconstruction (IR) is a safe and effective surgical treatment for patients with breast cancer. We aimed to assess the prognosis, aesthetic outcomes, and patient satisfaction of IR compared with breast conservation surgery (BCS) and total mastectomy (TM). METHODS: This retrospective matched-cohort study was conducted between May 2005 and December 2014. We established two cohorts according to the tumor (T) size of breast cancer. In the T≤3cm group, cases (IR) and controls (BCS or TM) were matched for age, pathological tumor size, and pathologic nodal status in a 1:1:1 ratio. In the T>3cm group, cases (IR) and controls (TM) were matched with the same factors and ratio. The primary outcome was the 5-year disease-free survival (DFS). The secondary outcome was patient satisfaction and quality of life. RESULTS: A total of 12,678 breast cancer patients were assessed for eligibility, of which 587 were included (T≤3 cm group: 155 IR vs 155 BCS vs 155 TM; T>3cm group: 61 IR vs 61 TM). In the T≤3 cm cohort, patients who underwent IR had no difference compared with those who underwent BCS or TM regarding the 5-year DFS (P=0.539); however, an improved aesthetic satisfaction, psychosocial, and sexual well-being were achieved in the IR group (P<0.001). In the T>3 cm cohort, the IR group had a worse median 5-year DFS (P=0.044), especially for Her2+ or triple-negative breast carcinoma (TNBC) subtypes compared with the TM group. CONCLUSIONS: IR improves aesthetic satisfaction, psychosocial, and sexual well-being for breast cancer patients with T≤3 cm. For patients with T > 3 cm invasive breast cancer, TM is superior to IR as it predicts a better 5-year DFS.

A Reliable Method for Chin Augmentation by Mechanical Micronization of Lipoaspirates.

BACKGROUND: Desire for improved aesthetic contour of the lower third of the face has resulted in an increase in chin augmentation. Although many fillers, including hyaluronic acid (HA), autologous fat and stromal vascular fraction gel (SVF-gel), have been used to improve facial morphology, chin augmentation requires fillers that provide greater support. METHODS: The elastic and viscous moduli of SVF-gel and Coleman fat were assessed in vitro by rheological testing, whereas their elasticity were evaluated in vivo by ultrasonic elastography. Results in vitro were compared with those of highly elastic HA (HE-HA) and highly viscous HA (HV-HA), whereas results in vivo were compared with HE-HA. Changes in chin volume, SVF-gel retention rate and absorptivity for at least 12 months were measured by 3D white light scanning. Questionnaires were administered to assess patient satisfaction. RESULTS: The elastic and viscous modulus of SVF-gel was, respectively, slightly lower than HE-HA and HV-HA but higher than the other two in vitro, with the elasticity of the three layers of SVF-gel lower than HE-HA but slightly higher than normal control in vivo. The average retention rate was 62.34±3.34% at 12 months. The absorptivity of 90% of the samples was <3% from 6 to 12 months, which was considered stable. Patients expressed satisfaction with their results. CONCLUSION: SVF-gel has ideal rheologic characteristics in vitro, which has slightly higher elasticity than normal fat tissue of chin in vivo, and could keep well retention rate for chin augmentation in clinic. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

An Efficacy Study of a New Radical Treatment for Acne Vulgaris Using Fat Injection.

BACKGROUND: Fat grafting is a popular operative approach for rejuvenation. Some patients requiring facial fat grafting also have acne. Fat grafting may improve acne in some patients. OBJECTIVES: The aim of this study was to assess whether fat grafting can improve acne and to analyze the mechanism of action by which such improvement occurs. METHODS: Preoperative and postoperative digital photographs were examined retrospectively in 229 patients who underwent fat grafting to compare the numbers of inflammatory acne lesions. In addition, 18 patients with acne who were treated by injection of subdermal stromal vascular fraction gel (SVF-gel) were examined prospectively. The numbers of inflammatory acne lesions before and after treatment were measured, and changes in the levels of CD4+ T-cell infiltration were determined from immunohistochemical staining. RESULTS: Of the 229 retrospectively evaluated patients who underwent fat grafting, 22 had acne and had complete follow-up data; in these patients, the numbers of acne lesions were significantly lower after than before treatment. The 18 patients who received subdermal SVF-gel injection showed evident improvements in inflammatory lesions after more than 1 year of follow-up. CD4+ T-cell infiltration was significantly decreased at week 4. CONCLUSIONS: Facial fat grafting can improve inflammatory acne lesions, perhaps because adipose-derived stem cells, which are plentiful in SVF-gel, reduce CD4+ T-cell-mediated inflammation responses.

Correction of the Tear Trough Deformity and Concomitant Infraorbital Hollows With Extracellular Matrix/Stromal Vascular Fraction Gel.

BACKGROUND: The tear trough deformity is a sign of eye aging. Filling is an ideal choice for the tear trough accompanied by infraorbital hollows. OBJECTIVE: To evaluate the efficacy and safety of stromal vascular fraction gel (SVF-gel) as a filler for the tear trough deformity which is combined with infraorbital hollows. MATERIALS AND METHODS: From July 2017 to June 2018, 33 patients underwent autologous fat aspiration and were followed up successfully. Stromal vascular fraction gel was used to correct patients with bilateral Barton I/II; tear trough deformity and infraorbital hollows. Improvement was evaluated by measuring skin-periosteal depth, 3D volume, global aesthetic improvement scale (GAIS), and patient self-assessment. RESULTS: Skin-periosteal depth improved significantly (p < .001). The volumetric increment of the tear trough and infraorbital regions increased 2.132 ± 0.671 mL, and the retention rate was excellent (72.87 ± 10.23%). The GAIS showed a high score (2.5 ± 0.5 points), with patient self-assessment showing satisfactory results for all 7 questions on the questionnaire. CONCLUSION: The high retention rate of SVF-gel suggests that it can provide an effective solution to tear trough deformity accompanied by infraorbital hollows.

Coupling PtNi Ultrathin Nanowires with MXenes for Boosting Electrocatalytic Hydrogen Evolution in Both Acidic and Alkaline Solutions.

Developing an efficient electrocatalyst for the hydrogen evolution reaction (HER) working in both acidic and alkaline solutions is highly desirable, but still remains challenging. Here, Ptx Ni ultrathin nanowires (NWs) with tunable compositions (x = 1.42, 3.21, 5.67) are in situ grown on MXenes (Ti3 C2 nanosheets), serving as electrocatalysts toward HER. Such Ptx Ni@Ti3 C2 electrocatalysts exhibit excellent HER performance in both acidic and alkaline solutions, with the Pt3.21 Ni@Ti3 C2 being the best one. Specifically, Pt3.21 Ni@Ti3 C2 achieves record-breaking performance in terms of lowest overpotential (18.55 mV) and smallest Tafel slope (13.37 mV dec-1 ) for HER in acidic media to date. Theory calculations and X-ray photoelectron spectroscopy analyses demonstrate that the coupling of MXenes with the NWs not only approaches the Gibbs free energy for hydrogen adsorption close to zero through the electron transfer between them in acidic media, but also provides additional active sites for water dissociation in alkaline solution, both of them being beneficial to the HER performance.

Surface faceting and compositional evolution of Pd@Au core-shell nanocrystals during in situ annealing.

Bimetallic core-shell nanoparticles have received considerable attention for their unique optical, magnetic and catalytic properties. However, these properties will be dramatically modified under ambient conditions by their structure and/or composition change. Thus, it is of primary importance to study the complex transformation pathway of core-shell nanoparticles at an elevated temperature. In this work, by using an aberration-corrected scanning transmission electron microscope equipped with an energy dispersive X-ray mapping system, the complete transformation process from a well-designed Pd@Au core-shell nanoparticle to a uniform alloy particle was visualized. It is revealed that this transformation process went through three steps, i.e., surface refacetting, particle resphering and complete alloying. Combining with a developed atomic kinetic Monte Carlo simulation, we found that surface energy is the driving force for shape variation, and the different atomic activation barriers of surface diffusion and bulk migration result in the multistep transformation pathway. Our results offered important information for understanding the structure evolution of bimetallic core-shell nanoparticles, which is beneficial for the rational design of nanoparticles with kinetic stability.

Wnt/ß-Catenin Signaling Exacerbates Keloid Cell Proliferation by Regulating Telomerase.

OBJECTIVES: Our goal was to investigate the relationship between keloid and telomerase as well as clarifying the influence of Wnt/ß-catenin signaling on keloid cell proliferation. METHODS: Tissues from 18 keloid patients were collected for further study. Keloid progenitor cells (KPC) and skin progenitor cells (SKP) were both included in this study. Lenti-virus transfection was used to divide cells into different groups in which cells were treated with different substances: negative control (NC) group, wnt10a siRNA group, ß-catenin siRNA group and TERT siRNA group. KPC cells were injected into 20 male BALB/c nude mice in order to build tumor models. Several experiments including immunohistochemistry, western blot and RT-PCR were conducted in order to detect the corresponding protein expressions and relative mRNA levels. MTT assay and flow cytometry were also conducted for assessing cell proliferation and apoptosis status. RESULTS: ß-catenin and telomerase expression levels in keloid tissues were elevated compared to normal tissues (all P < 0.05). KPC cells in keloid exhibited more dynamic telomerase activity than SKP cells (P < 0.05). Luciferase activity assay confirmed that ß-catenin could directly interact with telomerase. After wnt10a/ß-catenin signaling pathway was inhibited, the proliferation of KPC cells was significantly suppressed and the apoptosis rate was remarkably increased (all P < 0.05). Results from tumor models also validated that wnt10a/ß-catenin signaling pathway influenced the activity and length of telomerase. CONCLUSIONS: Wnt/ß-catenin signaling pathway is able to exacerbate keloid cell proliferation and inhibit the apoptosis of keloid cells through its interaction with telomerase.

Effects of Medical Chitosan on Capsular Formation Following Silicone Implant Insertion in a Rabbit Model.

BACKGROUND: Capsular contracture is a serious complication that occurs after breast implant surgery. This study was performed to confirm that medical chitosan (MC) affects capsule formation and elucidates a possible mechanism. MATERIALS AND METHODS: In this study, we used 18 female adult New Zealand White rabbits. In each rabbit, two silicone implants were placed under the pectoralis muscle layer on both sides (one side was included in the experimental group and the other side was included in the control group). MC was applied around the silicone implant of the experiment group, while the control group received no treatment. The capsular thickness was calculated by Masson's trichrome stain. The expression of MMPs and TIMPs were determined by real-time PCR, Western blotting, and immunohistochemistry. RESULTS: Compared to the control group, the capsular thickness of the MC group was significantly reduced at 4, 8, and 12 weeks after the operation (4 week: 229.3 ± 72.2 vs 76.1 ± 12.6 µm, p < 0.05; 8 week: 326.0 ± 53.8 vs 155.4 ± 61.7 µm, p < 0.0.5; 12 week: 151.2 ± 52.5 vs 60.0 ± 22.0 µm, p < 0.05). Compared to the control group, the MC group had significantly lower expressions of TIMP-1 and TIMP-2 (p < 0.05). However, compared to the control group, there was no statistically significant difference in the expressions of MMP-2 and MMP-9 in the experiment group (p > 0.05). CONCLUSION: MC reduced the risk of developing capsular contracture around silicone implants, possibly by blocking the signaling pathway of TIMPs. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.