Drug-coated balloon angioplasty with provisional stenting versus primary stenting for the treatment of de novo coronary artery lesions: REC-CAGEFREE I trial rationale and design.

BACKGROUND: Percutaneous coronary intervention (PCI) with primary stenting, which stands for stent implantation regardless of obtaining satisfactory results with balloon angioplasty, has superseded conventional plain old balloon angioplasty with provisional stenting. With drug-coated balloon (DCB), primary DCB angioplasty with provisional stenting has shown non-inferiority to primary stenting for de novo coronary small vessel disease. However, the long-term efficacy and safety of such a strategy to the primary stenting on clinical endpoints in de novo lesions without vessel diameter restrictions remain uncertain. STUDY DESIGN: The REC-CAGEFREE I is an investigator-initiated, multicenter, randomized, open-label trial aimed to enroll 2270 patients with acute or chronic coronary syndrome from 43 interventional cardiology centers in China to evaluate the non-inferiority of primary paclitaxel-coated balloons angioplasty to primary stenting for the treatment of de novo, non-complex lesions without vessel diameter restrictions. Patients who fulfill all the inclusion and exclusion criteria and have achieved a successful lesion pre-dilatation will be randomly assigned to the two arms in a 1:1 ratio. Protocol-guided DCB angioplasty and bailout stenting after unsatisfactory angioplasty are mandatory in the primary DCB angioplasty group. The second-generation sirolimus-eluting stent will be used as a bailout stent in the primary DCB angioplasty group and the treatment device in the primary stenting group. The primary endpoint is the incidence of Device-oriented Composite Endpoint (DoCE) within 24 months after randomization, including cardiac death, target vessel myocardial infarction, and clinically and physiologically indicated target lesion revascularization. DISCUSSION: The ongoing REC-CAGEFREE I trial is the first randomized trial with a clinical endpoint to assess the efficacy and safety of primary DCB angioplasty for the treatment of de novo, non-complex lesions without vessel diameter restrictions. If non-inferiority is shown, PCI with primary DCB angioplasty could be an alternative treatment option to primary stenting. TRIAL REGISTRATION: Registered on clinicaltrial.gov (NCT04561739).

Identification of WxL and S-Layer Proteins from Lactobacillus brevis with the Ability to Bind Cellulose and Xylan.

Xylanase releases xylo-oligosaccharides from dietary xylan, which stimulate the growth of the gut bacteria lactobacilli. Many lactobacilli adhere to dietary fibers, which may facilitate the assimilation of xylo-oligosaccharides and help them gain competence in the gut, but the underlying mechanisms remain elusive. Herein we report, from the highly abundant transcripts of Lactobacillus brevis cultured in wheat arabinoxylan supplemented with a xylanase, the identification of genes encoding four putative cell-surface WxL proteins (Lb630, Lb631, Lb632, and Lb635) and one S-layer protein (Lb1325) with either cellulose- or xylan-binding ability. The repetitively occurring WxL proteins were encoded by a gene cluster, among which Lb630 was chosen for further mutational studies. The analysis revealed three aromatic residues (F30, W61, and W156) that might be involved in the interaction of the protein with cellulose. A homology search in the genome of Enterococcus faecium identified three WxL proteins with conserved counterparts of these three aromatic residues, and they were also found to be able to bind cellulose and xylan. The findings suggested a role of the cell-surface WxL and S-layer proteins in assisting the cellular adhesion of L. brevis to plant cell wall polysaccharides.

Clinical evaluation of fenestration decompression combined with secondary curettage for ameloblastoma of the jaw: retrospective radiographic analysis.

BACKGROUND: Ameloblastoma is a benign odontogenic epithelial tumor with local infiltration and a high recurrence rate that occurs most frequently in the jawbone. The aim of this study was to investigate the outcomes of fenestration decompression combined with secondary curettage (FDSC) in the surgical treatment of jaw ameloblastoma, and clarify the possibility of FDSC to become an appropriate therapeutic method for ameloblastoma with large lesion. METHODS: A retrospective analysis was carried out in 145 patients diagnosed with multicystic ameloblastoma (MA) and 88 patients with unicystic ameloblastoma (UA). These patients were divided into two groups based on the therapeutic regimen: the FDSC group and the local curettage (LC) group. Panoramic radiography was taken 2 years after curettage to evaluate the change in lesion area in each case, and the therapeutic effects of different treatment methods were further assessed by the chi square test. RESULTS: For MA, the effective rate of cystic cavity area reduction in the FDSC group (71.19%) was higher than that in the LC group (30.23%) (P < 0.001). For UA patients, the effective rate of lesion area reduction after FDSC was 93.02%, which was higher than that after LC (53.33%) (P < 0.001). Moreover, the recurrence rate of the FDSC group in the MA was 30.51%, which was significantly different from that of the LC group (P < 0.001). Regarding UA, the recurrence rates were 13.95% and 28.89%, after FDSC and LC, respectively, with no significant differences between the two groups (P > 0.05). CONCLUSIONS: FDSC exhibits a much better curative effect than LC in both MA and UA, whereas the recurrence rate of these two therapeutic strategies did not significantly differ in UA. The above data demonstrated that FDSC may serve as a routine, safe, effective and appropriate surgical treatment plan for MA or UA patients with large lesions.

Strategies To Design and Synthesize Polymer-Based Stimuli-Responsive Drug-Delivery Nanosystems.

The emergence and development of nanomedicine have alleviated problems existing in traditional chemotherapy drugs, such as short lifetime, concomitant side effects, and weak tumor-targeting capability. Nevertheless, the further applications of drug-loaded nanocarriers are still limited by their premature leakage, weak targeting capability, and insufficient intracellular release. In past decades, various nanocarriers, including gold nanoparticles, porous silica nanoparticles, carbon-based nanoparticles, micelles, liposomes, and polymer-drug conjugates, have been intensively investigated for tumor therapy. Among these, polymer-based nanocarriers have attracted more attention due to their biocompatibilities and capability of being modified for stimuli-responsive drug release. In this review, three popular strategies to design and synthesize polymer-based stimuli-responsive nanocarriers are discussed. The discussion goes from stimuli-responsive polymers with responsive backbones or modified by responsive functional groups for drug encapsulation and release to polymer-drug conjugates with responsive covalent linkages. In particular, due to the facile synthetic processes and mild reaction conditions for crosslinked structures, the latest progress in responsive crosslinked structures is emphasized. Finally, future perspectives for these nanomaterials are given, which are expected to provide inspiration for researchers to design more effective and safer tumor-killing nanomedicines.

Gradient Redox-Responsive and Two-Stage Rocket-Mimetic Drug Delivery System for Improved Tumor Accumulation and Safe Chemotherapy.

Recent drug delivery nanosystems for cancer treatment still suffer from the poor tumor accumulation and low therapeutic efficacy due to the complex in vivo biological barriers. To resolve these problems, in this work, a novel gradient redox-responsive and two-stage rocket-mimetic drug nanocarrier is designed and constructed for improved tumor accumulation and safe chemotherapy. The nanocarrier is constructed on the basis of the disulfide-doped organosilica-micellar hybrid nanoparticles and the following dual-functional modification with disulfide-bonded polyethylene glycol (PEG) and amido-bonded polyethylenimine (PEI). First, prolonged circulation duration in the bloodstream is guaranteed due to the shielding of the outer PEG chains. Once the nanocarrier accumulates at the tumoral extracellular microenvironment with low glutathione (GSH) concentrations, the first-stage redox-responsive behavior with the separation of PEG and the exposure of PEI is triggered, leading to the improved tumor accumulation and cellular internalization. Furthermore, with their endocytosis by tumor cells, a high concentration of GSH induces the second-stage redox-responsiveness with the degradation of silsesquioxane framework and the release of the encapsulated drugs. As a result, the rocket-mimetic drug carrier displays longer circulation duration in the bloodstream, higher tumor accumulation capability, and improved antitumor efficacy (which is 2.5 times higher than that with inseparable PEG). It is envisioned that the rocket-mimetic strategy can provide new solutions for improving tumor accumulation and safety of nanocarriers in further cancer chemotherapy.

Revisiting overexpression of a heterologous ß-glucosidase in Trichoderma reesei: fusion expression of the Neosartorya fischeri Bgl3A to cbh1 enhances the overall as well as individual cellulase activities.

BACKGROUND: The filamentous fungus Trichoderma reesei has the capacity to secret large amounts of cellulase and is widely used in a variety of industries. However, the T. reesei cellulase is weak in ß-glucosidase activity, which results in accumulation of cellobiose inhibiting the endo- and exo-cellulases. By expressing an exogenous ß-glucosidase gene, the recombinant T. reesei cellulase is expected to degrade cellulose into glucose more efficiently. RESULTS: The thermophilic ß-glucosidase NfBgl3A from Neosartorya fischeri is chosen for overexpression in T. reesei due to its robust activity. In vitro, the Pichia pastoris-expressed NfBgl3A aided the T. reesei cellulase in releasing much more glucose with significantly lower amounts of cellobiose from crystalline cellulose. The NfBgl3A gene was hence fused to the cbh1 structural gene and assembled between the strong cbh1 promoter and cbh1 terminator to obtain pRS-NfBgl3A by using the DNA assembler method. pRS-NfBgl3A was transformed into the T. reesei uridine auxotroph strain TU-6. Six positive transformants showed ß-glucosidase activities of 2.3-69.7 U/mL (up to 175-fold higher than that of wild-type). The largely different ß-glucosidase activities in the transformants may be ascribed to the gene copy numbers of NfBgl3A or its integration loci. The T. reesei-expressed NfBgl3A showed highly similar biochemical properties to that expressed in P. pastoris. As expected, overexpression of NfBgl3A enhanced the overall cellulase activity of T. reesei. The CBHI activity in all transformants increased, possibly due to the extra copies of cbh1 gene introduced, while the endoglucanase activity in three transformants also largely increased, which was not observed in any other studies overexpressing a ß-glucosidase. NfBgl3A had significant transglycosylation activity, generating sophorose, a potent cellulase inducer, and other oligosaccharides from glucose and cellobiose. CONCLUSIONS: We report herein the successful overexpression of a thermophilic N. fischeri ß-glucosidase in T. reesei. In the same time, the fusion of NfBgl3A to the cbh1 gene introduced extra copies of the cellobiohydrolase 1 gene. As a result, we observed improved ß-glucosidase and cellobiohydrolase activity as well as the overall cellulase activity. In addition, the endoglucanase activity also increased in some of the transformants. Our results may shed light on design of more robust T. reesei cellulases.

Effectiveness of ruminal xylanase with an extra proline-rich C-terminus on lignocellulosic biomass degradation.

The efficient degradation of plant polysaccharides in agricultural waste requires xylanases with high catalytic activity. In this study, the C-terminal proline-rich GH10 xylanase XynA from sheep rumen was investigated using product analysis, structural characterization, truncated and site-directed mutagenesis, molecular dynamics simulation, and application evaluation, revealing that the proline-rich C-terminus contributes to the interaction at the substrate-binding pocket to reduce the binding free energy. Compared to the C-terminally truncated enzyme XynA-Tr, XynA has a more favorable conformation for proton transfer and affinity attack, facilitating the degradation of oligomeric and beechwood xylan without altering the hydrolysis pattern. Moreover, both the reduced sugar yield and weight loss of the pretreated wheat bran, corn cob, and corn stalk hydrolyzed by XynA for 12 h increased by more than 30 %. These findings are important to better understand the relationship between enzyme activities and their terminal regions and suggest candidate materials for lignocellulosic biomass utilization.

A confined crosslinking strategy towards an intelligent organosilica-micellar hybrid drug delivery system.

An ideal drug delivery system must have a high level of stability to ensure effective circulation and passive aggregation, good retention performance, and dynamic delivery and treatment monitoring. Thus, the development of a smart drug delivery carrier with both precise drug release and real-time detection remains a challenge. Herein, we propose a confined crosslink protocol to prepare an intelligent hybrid delivery system for auto-fluorescent monitoring, protonation-induced retention and precise drug release. The construction of this system involves the hydrolysis and condensation of (3-aminopropyl)triethoxysilane (APTES) silanes inside the Pluronic polymer micelles and thereafter a confined Schiff base crosslinking between glutaraldehyde (GA) and residual silane amino groups. The size of the intelligent docetaxel (DTX)-loaded nanosystem changes from ∼25 nm in blood circulation or normal tissues (pH ∼ 7.4) to ∼250 nm in slightly acidic environments (pH ∼ 6.5-7.0) owing to intra-molecular hydrogen bond-induced aggregation and imine cleavage-induced disintegration in the endosome (pH ∼ 5.0-6.2) along with auto-fluorescent monitoring contributing to the high-efficiency chemotherapy. This work provides a new method to construct smart, acid-responsive and fluorescent-guided drug-delivery carrier systems for efficient and safe tumor chemotherapy.

Boosting enzymatic degradation of cellulose using a fungal expansin: Structural insight into the pretreatment mechanism.

The recalcitrance of cellulosic biomass greatly hinders its enzymatic degradation. Expansins induce cell wall loosening and promote efficient cellulose utilization; however, the molecular mechanism underlying their action is not well understood. In this study, TlEXLX1, a fungal expansin from Talaromyces leycettanus JCM12802, was characterized in terms of phylogeny, synergy, structure, and mechanism of action. TlEXLX1 displayed varying degrees of synergism with commercial cellulase in the pretreatment of corn straw and filter paper. TlEXLX1 binds to cellulose via domain 2, mediated by CH-π interactions with residues Tyr291, Trp292, and Tyr327. Residues Asp237, Glu238, and Asp248 in domain 1 form hydrogen bonds with glucose units and break the inherent hydrogen bonding within the cellulose matrix. This study identified the expansin amino acid residues crucial for cellulose binding, and elucidated the structure and function of expansins in cell wall networks; this has potential applications in biomass utilization.

Deciphering the efficient cellulose degradation by the thermophilic fungus Myceliophthora thermophila focused on the synergistic action of glycoside hydrolases and lytic polysaccharide monooxygenases.

The thermophilic fungus Myceliophthora thermophila as an efficient decomposer secretes various glycoside hydrolases and auxiliary oxidation enzymes to deconstruct cellulose. However, the core enzymes critical for efficient cellulose degradation and their interactions with other cellulolytic enzymes remain unclear. Herein, the transcriptomic analysis of M. thermophila grown on Avicel exhibited that cellulases from GH5_5, GH6 and GH7, and lytic polysaccharide monooxygenases (LPMOs) from AA9 contributed to cellulose degradation. Moreover, the peptide mass fingerprinting analysis of major extracellular proteins and corresponding gene-knockout strains studies revealed that MtCel7A and MtCel5A were the core cellulolytic enzymes. Furthermore, synergistic experiments found that hydrolytic efficiencies of MtCel7A and MtCel5A were both improved by mixture C1/C4 oxidizing MtLPMO9H, but inhibited by C1 oxidizing MtLPMO9E and C4 oxidizing MtLPMO9J respectively. These results demonstrated the potential application of C1/C4 oxidizing LPMOs for future designing novel cellulolytic enzyme cocktails on the efficient conversion of cellulose into biofuels and biochemicals.

Peroxisome inspired hybrid enzyme nanogels for chemodynamic and photodynamic therapy.

Peroxisome, a special cytoplasmic organelle, possesses one or more kinds of oxidases for hydrogen peroxide (H2O2) production and catalase for H2O2 degradation, which serves as an intracellular H2O2 regulator to degrade toxic peroxides to water. Inspired by this biochemical pathway, we demonstrate the reactive oxygen species (ROS) induced tumor therapy by integrating lactate oxidase (LOx) and catalase (CAT) into Fe3O4 nanoparticle/indocyanine green (ICG) co-loaded hybrid nanogels (designated as FIGs-LC). Based on the O2 redistribution and H2O2 activation by cascading LOx and CAT catalytic metabolic regulation, hydroxyl radical (·OH) and singlet oxygen (1O2) production can be modulated for glutathione (GSH)-activated chemodynamic therapy (CDT) and NIR-triggered photodynamic therapy (PDT), by manipulating the ratio of LOx and CAT to catalyze endogenous lactate to produce H2O2 and further cascade decomposing H2O2 into O2. The regulation reactions of FIGs-LC significantly elevate the intracellular ROS level and cause fatal damage to cancer cells inducing the effective inhibition of tumor growth. Such enzyme complex loaded hybrid nanogel present potential for biomedical ROS regulation, especially for the tumors with different redox state, size, and subcutaneous depth.

Application of problem-based learning in a large class in stomatology course.

PURPOSE: To determine the feasibility of implementing problem-based learning (PBL) in a large class and whether previous PBL experience is necessary. MATERIALS AND METHODS: A total of 236 students from 2 large classes at China Medical University were enrolled. One class (118 students) had had a previous small-group PBL experience and another class (113 students) had not. Each class was subdivided into 15 groups (7 to 8 students/group) and took 2 separate 100-minute PBL sessions per week with the same teaching faculty. Each PBL class had 2 facilitators, 1 content expert facilitator, and 1 nonexpert facilitator. The results of the theoretical examination and case analysis examinations were analyzed using the t test. Questionnaires were used to evaluate both student and facilitator perceptions. RESULTS: The feedback from both students and facilitators was positive. According to the questionnaires, both experienced and non-experienced students acknowledged that the teaching method was enjoyable and functional. The test results showed students had achieved the learning objectives. The results of the theoretical and case analysis examinations showed no significant difference between the PBL experienced class and the non-experienced class. The mean study hours spent weekly by the students after class on the course were about 6.3 +/- 1.1 hours for the non-experienced students and 4.7 +/- 0.981 hours for the experienced students (t = 11.94, P < .001). The non-experienced students showed more preference for the content expert tutor. CONCLUSION: Implementing PBL in a large class is feasible without extracting great demand on limited educational resources. Previous PBL experience is helpful but not necessary.

Heterologous expression and characterization of a xylanase and xylosidase from white rot fungi and their application in synergistic hydrolysis of lignocellulose.

Endo-xylanase and ß-xylosidase are the major enzymes for hemicellulose hydrolysis, which play a significant role in biomass conversion. In our previous work, the white-rot fungi Pleurotus ostreatus HAUCC 162 and Irpex lacteus CD2 were demonstrated to have strong ability in lignocellulose degradation, and the related lignin degradation enzymes were characterized. However, little was known about their hemicellulases. In this work, a novel endo-1, 4-xylanase and a ß-xylosidase from Pleurotus ostreatus HAUCC 162 and Irpex lacteus CD2 were heterologously expressed and characterized. The optima of pH and temperature were 5.0 and 55 °C for rXyn162, and 6.5 and 30 °C for rXylCD2. rXyn162 showed high tolerance to metal ions such as Ca2+, Cr3+, Zn2+, Na+, and Al3+. The recombinant rXyn162 and rXylCD2 exhibited synergistic hydrolysis of oat spelts xylan and sodium hydroxide pretreated cornstalk (SHPC), where the degree of synergy (DS) was 2.26 for SHPC hydrolysis. MALDI-TOF-MS and HPLC analysis showed that xylooligosaccharides (XOS) with small degrees of polymerization (DP2-DP4) were the major XOS hydrolyzate during SHPC degradation by rXyn162 and rXylCD2. In addition, rXyn162 and rXylCD2 could efficiently improve the hydrolysis of SHPC by commercial cellulase. The present study suggested the potential application of rXyn162 and rXylCD2 in the field of biomass pretreatment and biofuel production.

Management strategy in patient with familial gigantiform cementoma: A case report and analysis of the literature.

RATIONALE: Familial gigantiform cementoma (FGC) is a rare benign autosomal dominant fibrocemento-osseous lesion generally limited to the facial bones, typically in the anterior portion of the mandible; it is often associated with abnormalities of the long bones and prepubertal pathologic fractures. Owing to the small number of such patients, a uniform treatment criterion has not been established. This paper presents a patient with FGC who was treated in our department, and offers a systematic review of the patients reported in the literature. Our aim was to explore the treatment strategy for patients with FGC. PATIENT CONCERNS: Our patient, a 13-year-old boy, presented with a painless enlargement of the mandible first noted 2 years earlier. It had grown rapidly over the preceding 8 months, affecting both his appearance and ability to chew. DIAGNOSIS: Based on the pathologic, clinical, and radiographic features, FGC was diagnosed. INTERVENTIONS: Mandibuloectomy was performed. The mandibular defect was immediately reconstructed with his right vascularized iliac crest flap. At the same time, a PubMed search was conducted to identify studies reporting on other patients with FGC. OUTCOMES: A 3-dimensional computed tomography (3D-CT) scan demonstrated appropriate height of the new alveolar bone. Follow-up results showed recovery of the patient's appearance and mandibular function. He was free of recurrence at 4-year follow-up. LESSONS: FGC is a rare benign fibrocemento-osseous lesion of the jaws that can cause severe facial deformity. Incomplete removal leads to more rapid growth of the residual lesion. Therefore, extensive resection is a suitable strategy to avoid recurrence. Defects of the facial bones found intraoperatively should be repaired with resort to an appropriate donor site. However, it is important to be aware that patients with FGC always have concomitant abnormalities of skeletal metabolism and structure, as well as a vulnerability to fractures of the long bones of the lower extremity. Therefore, the optimal management strategy should include a review of treatment options for other patients as reported in the literature. An optimal protocol can not only provide sufficient high-quality bone suitable for the reconstruction of bone defects, but also minimize complications and maximize quality of life.

A modified technique for reconstruction of a total maxillary defect.

Total maxillary defects with orbital retention (Brown class 2b) are a challenge to reconstructive surgeons because of the variety of anatomical structures involved. Traditional techniques to reconstruct the orbital floor, zygoma, and maxilla using only a vascularised fibular flap are complicated, as the osteotomy and orientation of bone are difficult. Reconstruction of the orbital floor with titanium mesh may also cause palpable discomfort and increase the risk of secondary infection. We describe a modified technique using a vascularised fibular flap, together with a coronoid temporalis pedicle flap, which we used in two patients in whom we achieved satisfactory aesthetic and functional results. Our technique provides adequate tissue for infraorbital skin defects, provides pedicles of sufficient length, and requires only one fibular osteotomy. To our knowledge this is the first report of this technique.

Genomic and molecular mechanisms for efficient biodegradation of aromatic dye.

Understanding the molecular mechanisms for aromatic compound degradation is crucial for the development of effective bioremediation strategies. We report the discovery of a novel phenomenon for improved degradation of Direct Red 5B azo dye by Irpex lacteus CD2 with lignin as a co-substrate. Transcriptomics analysis was performed to elucidate the molecular mechanisms of aromatic degradation in white rot fungus by comparing dye, lignin, and dye/lignin combined treatments. A full spectrum of lignin degradation peroxidases, oxidases, radical producing enzymes, and other relevant components were up-regulated under DR5B and lignin treatments. Lignin induced genes complemented the DR5B induced genes to provide essential enzymes and redox conditions for aromatic compound degradation. The transcriptomics analysis was further verified by manganese peroxidase (MnP) protein over-expression, as revealed by proteomics, dye decolorization assay by purified MnP and increased hydroxyl radical levels, as indicated by an iron reducing activity assay. Overall, the molecular and genomic mechanisms indicated that effective aromatic polymer degradation requires synergistic enzymes and radical-mediated oxidative reactions to form an effective network of chemical processes. This study will help to guide the development of effective bioremediation and biomass degradation strategies.

Alveolar soft part sarcoma of the oral and maxillofacial region: clinical analysis in a series of 18 patients.

OBJECTIVES: To summarize the clinical features, diagnosis, treatment strategies, and prognosis of alveolar soft part sarcoma (ASPS) of the oral and maxillofacial region. STUDY DESIGN: We performed a retrospective study in a consecutive series of 18 patients with ASPS of the oral and maxillofacial region between 1995 and 2013. Demographic characteristics, tumor sizes, sites, tumor metastasis, diagnosis, treatments, and overall follow-ups were documented. RESULTS: The 18 patients were diagnosed pathologically with primary tumor developed on the tongue (10), the cheek (5), the pharynx (1), and the gingiva (2) with an average tumor size of 4 cm. At the latest follow-up, 1 patient with lung metastases survived for 23 months; 1 died 3 months after the confirmation of local recurrence and multiple pulmonary metastases; the rest of the patients were disease free and remained in good health. CONCLUSIONS: ASPS of the oral and maxillofacial region appears to have special clinical characteristics.

[Perforator-based chimeric anterolateral thigh flap for head and neck reconstruction after en bloc resection].

PURPOSE: To discuss and report the operative techniques for harvesting perforator-based chimeric flap in anterolateral thigh region and the advantages for head and neck reconstruction after en bloc resection. METHODS: A retrospective review was performed of perforator-based chimeric anterolateral thigh (ALT) flap for head and neck reconstruction since December of 2007 to March of 2011. 66 perforator-based chimeric flaps were harvested including a skin paddle and a muscular flap supplied by one mother pedicle-descending branch of lateral circumflex femoral artery(d-LCFA). 32 flaps were used for the mobile tongue and floor of mouth reconstruction, 30 flaps for base of the tongue and parapharyngeal walls, two for the buccal skin, one for hemimandible and one for parotid. The muscular flap were used to eliminate the dead space of submandibular area. Flaps size ranged from 7cm±4cm to 16cm±7cm and muscular flap was 3cm±4cm approximately. The complications and functions of both donor and recipient sites were recorded and the operative techniques of perforator-based chimeric flap elevation were generalized. RESULTS: All 65 flaps survived completely and the total survival percentage was 98.5%. Only one flap failed and was removed 5 days postoperatively. No complications(fistula, infection, hematoma, seroma et al) were observed in recipient and donor sites. Two anteromedial thigh flaps (AMT) were used for reconstruction due to no sizable perforators in the ALT region. All cases were followed up for 0.5-3 years. The flaps didn't atrophy after six months and the contour was satisfactory. The functions of speech and swallow were recovered well. All the donor sites were closed primarily and the scar was not obvious. The leg's function recovered well. CONCLUSIONS: Using a combination of retrograde and antegrade dissection is a safe and versatile method for harvesting a perforator-based chimeric flap. A chimeric flap including multiple components can meet the requirements of three-dimensional reconstruction. Perforator-based chimeric anterolateral thigh flap is one of the best choices for complex head and neck reconstruction after en bloc resection.

[Rehabilitation by hollow obturator prosthesis immediately after total maxillectomy for malignant tumor].

OBJECTIVE: The feasibility and clinical effects of hollow obturator prosthesis for the repair of maxillofacial defect immediately after maxillectomy for cancer were assessed. METHODS: Thirteen patients with T3-4aN0M0 maxillary neoplasm were treated by the prostheses immediately after maxillectomy. According to the 3D-CT reconstruction of nasal sinus, the 3D stereoscopic prototype was constructed before the surgery. Simulating surgery with Surgicare 5.0 software and then the prosthesis 3D stereoscopic model was shaped. The prosthesis was made quickly and precisely with methacrylate resins according to the model and the print mold before surgery, with supplementary tooth at the bottom of prosthesis. In the surgery, the prosthesis was installed instantly after maxillectomy. The patients were followed up at 1, 3 and 6 month after the surgery, respectively. The facial features and the pronunciation clarity were examined and the questionnaires were carried out in the patients, with comparation by paired t-test. The hollow obturator prosthesis would be replaced by permanent prosthesis made of methacrylate resins at 6 month after the surgery. RESULTS: The hollow obturator prostheses were installed accurately and maxillofacial defects were repaired immediately after maxillectomy in the 13 patients. Postoperative follow-up showed there were significant differences in eyeball sagging (t = 4.67, P < 0.05), mid-facial region collapse (t = 5.67, P < 0.05), and pronunciation clarity (t = 16.38, P < 0.05) between patients with and without prostheses. Questionnaires showed that all the patients were satisfied with the retention of prostheses, the improvement of appearance, the improvement of the symptom of water choking and speech definition. Six months after the surgery, the hollow obturator prostheses were replaced smoothly by permanent prostheses in 11 of the 13 patients. CONCLUSION: The precise and instant repair of maxillofacial defect by prosthesis after maxillectomy can improve survival quality of patient.