Removable partial prosthesis combined with swallowing training is an efficient clinical solution for oral cancer post-operation patients with palatal defect and dysphagia: a prospective study.

OBJECTIVE: Dysphagia is one of the major complications of oral cancer patients, and is disturbing thousands of patients worldwide. Our study aim to evaluate the clinical efficacy of prosthesis combined with swallowing training on palatal defect and dysphagia in post-operative oral cancer patients. MATERIALS AND METHODS: Sixteen oral cancer patients with palatal defect and dysphagia post-operation were treated with removable prosthesis and individualized swallowing function training. Swallowing function of patients before and after treatment was analyzed and compared by videofluoroscopic swallowing examination. The severity of depression and life quality were evaluated by Depression Scale (SDS) and Functional Assessment of Cancer Therapy-Head and Neck (FACT-H&N) scores, respectively. RESULTS: Oral transit time (OTT) significantly shortened after treatment (P < 0.01), and Penetration-Aspiration Scale (PAS) scores was significantly higher after treatment (P < 0.001). Different consistency bolus showed different risk of aspiration. Thickened liquids were related to lower PAS scores (P < 0.001). SDS standard score was significantly lower after treatment (P < 0.05). The total score of FACT-H&N after treatment was significantly higher (P < 0.05). No patients came back for regressed swallowing function during the follow-up period (17.06 ± 2.376 months). CONCLUSION: Removable prosthesis and swallowing training can significantly improve swallowing function, reduce depression degree, and improve quality of life (QOL). CLINICAL RELEVANCE: Removable prosthesis combined with swallowing training is a cheap and effective method to improve QOL in patients with palate defect and dysphagia after oral cancer.

A Novel Missense Variant in the TCOF1 Gene in one Chinese Case With Treacher Collins Syndrome.

The purpose of this study is to analyze the clinical characteristics of a Treacher Collins syndrome (TCS) patient carrying a de novo variant of TCOF1, and briefly analyze the correlation between genetic results and clinical features. Also, the pathogenesis and clinical treatment of TCS are reviewed.A Chinese pedigree with TCS containing 8 members was enrolled. Phenotype of the proband was evaluated by a surgeon, then whole exome sequencing of the proband was performed. Then we verified the proband-derived variants by Sanger sequencing in the pedigree. Correlation between genotype and phenotype was analyzed.The study was conducted in a stomatological hospital.A Chinese pedigree with TCS containing 8 members.To ascertain the genetic variants in the Chinese pedigree with TCS.Blood samples were collected.We reported a case of typical TCS with a de novo missense variant (NM_001371623.1:c.38T>G, p.(Leu13Arg)) in exon 1 of TCOF1, who presented asymmetrical facial abnormalities, including downward slanting of the palpebral fissures, sparse eyebrows, lateral tilt of the eyeballs, bilateral external ears deformities, hypoplasia of midface, reduction of the zygomatic body, bilateral orbital invagination, right external auditory canal atresia, mandibular ramus short deformity, cleft palate and the whole face was convex.This research found a novel variant of TCS in Chinese, expanding the spectrum of TCS pathogenic variants. Genetic results combined with clinical phenotype can make a definite diagnosis and provide genetic counseling for the family.

Preparation of PMMA Electrospun Fibers Bearing Porphyrin Pendants and Photocatalytic Degradation of Organic Dyes.

Porphyrins have a large π-π conjugation force between molecules, and they are easy to aggregate in solution, which affects the photoelectric properties of porphyrins. Connecting porphyrins to polymer links through covalent bonds not only retains the mechanical properties and thermal stability of polymer materials, but also has the photoelectric properties and catalytic properties of porphyrins, which improves the availability of materials. In this study, first, a porphyrin ligand with double bonds in the side chain was designed and the corresponding copper and zinc complexes were synthesized by adjusting the metal ions in the center of the pyrrole ring. Then, the metalloporphyrin complexes were copolymerized with methyl methacrylate (MMA), and two metalloporphyrin/PMMA copolymers were obtained: CPTPPCu/PMMA and CPTPPZn/PMMA. The structure of the compounds was characterized by IR, 1H NMR, MS, and UV-Vis spectra. Metalloporphyrin/PMMA copolymers were prepared into electrospun fiber materials by electrospinning. The morphology of the composites was studied by SEM, and the thermal stability and optical properties of electrospun fibers were studied by TGA and FL. The catalytic activity of electrospun fiber materials for the degradation of organic dyes was studied. The results showed that the efficiency of the metalloporphyrin/PMMA copolymer in photocatalytic degradation of methylene blue (MB) was better than that of the PMMA electrospun fiber blended with metalloporphyrin.

Three-dimensional poly-(ε-caprolactone) nanofibrous scaffolds directly promote the cardiomyocyte differentiation of murine-induced pluripotent stem cells through Wnt/ß-catenin signaling.

BACKGROUND: Environmental factors are important for stem cell lineage specification, and increasing evidence indicates that the nanoscale geometry/topography of the extracellular matrix (ECM) directs stem cell fate. Recently, many three-dimensional (3D) biomimetic nanofibrous scaffolds resembling many characteristics of the native ECM have been used in stem cell-based myocardial tissue engineering. However, the biophysical role and underlying mechanism of 3D nanofibrous scaffolds in cardiomyocyte differentiation of induced pluripotent stem cells (iPSCs) remain unclear. RESULTS: Here, we fabricated a 3D poly-(ε-caprolactone) (PCL) nanofibrous scaffold using the electrospinning method and verified its nanotopography and porous structure by scanning electron microscopy. We seeded murine iPSCs (miPSCs) directly on the 3D PCL nanofibrous scaffold and initiated non-directed, spontaneous differentiation using the monolayer method. After the 3D PCL nanofibrous scaffold was gelatin coated, it was suitable for monolayer miPSC cultivation and cardiomyocyte differentiation. At day 15 of differentiation, miPSCs differentiated into functional cardiomyocytes on the 3D PCL nanofibrous scaffold as evidenced by positive immunostaining of cardiac-specific proteins including cardiac troponin T (cTnT) and myosin light chain 2a (MLC2a). In addition, flow cytometric analysis of cTnT-positive cells and cardiac-specific gene and protein expression of cTnT and sarcomeric alpha actinin (α-actinin) demonstrated that the cardiomyocyte differentiation of miPSCs was more efficient on the 3D PCL nanofibrous scaffold than on normal tissue culture plates (TCPs). Furthermore, early inhibition of Wnt/ß-catenin signaling by the selective antagonist Dickkopf-1 significantly reduced the activity of Wnt/ß-catenin signaling and decreased the cardiomyocyte differentiation of miPSCs cultured on the 3D PCL nanofibrous scaffold, while the early activation of Wnt/ß-catenin signaling by CHIR99021 further increased the cardiomyocyte differentiation of miPSCs. CONCLUSION: These results indicated that the electrospun 3D PCL nanofibrous scaffolds directly promoted the cardiomyocyte differentiation of miPSCs, which was mediated by the activation of the Wnt/ß-catenin signaling during the early period of differentiation. These findings highlighted the biophysical role of 3D nanofibrous scaffolds during the cardiomyocyte differentiation of miPSCs and revealed its underlying mechanism involving Wnt/ß-catenin signaling, which will be helpful in guiding future stem cell- and scaffold-based myocardium bioengineering.

Biopolymers Production by Mixed Culture and Their Applications in Water and Wastewater Treatment.

Thirteen extracellular polymeric substances (EPS) producing bacterial strains were cultivated (as pure/mixed culture) in sterilized sludge (suspended solids: 25 g/L). The mixed culture produced higher concentrations of EPS (4.9 g/L) as compared to that of the pure culture (2.7-3.7 g/L). The harvested EPS were examined for their flocculation performance (turbidity removal and dewatering) in jar tests using kaolin suspensions with Ca2+. Broth (B-EPS) revealed high kaolin flocculating activity (91.2%) at very low concentrations (0.8 mg B-EPS/g kaolin) and it was comparable to the chemical polymer, Magnafloc-155 (90.4% at 0.2 mg/g kaolin). B-EPS also exhibited very good flocculation performance (turbidity removal %) in river water (93.5%), municipal wastewater (91.7%) and brewery wastewater (81.8%). The study revealed that the mixed culture consortium could be used for the production of highly efficient flocculants.

In-situ formation of thermo-responsive petal-like cellulose nanocrystals hybridized particles towards optimizing mechanical, rheological and dielectric properties of polylactic acid blends.

Enhancing the toughness of biodegradable polylactic acid (PLA) blends with minimal filler content meanwhile preserving their thermomechanical properties remains a highly desirable objective. Here, through a simple in situ mixing of PLA with cellulose nanocrystals (CNC) and cellulose nanocrystal nanofluids (CNCfs), the electrostatic interaction between CNCfs (+22.6 mv) and CNC (-9.07 mv) formed petal-like hybridized particles with CNCfs as the core and CNC particles as the outer layer. The rheological tests indicated a significant reduction in the zero-shear viscosity and storage modulus of PLA/CNCfs blends, while the viscosity of PLA/CNCfs@CNC slightly decreased but retained its storage modulus compared to pure PLA. The optimized PLA/CNCfs@CNC blends not only exhibited excellent melt processing performance, but also increased the elongation at break (increased by 184 % and 375 % at 8 °C and 45 °C, respectively) and enhanced toughness remarkably (increased by 3.5 and 3.3-fold at 8 °C and 45 °C, respectively) meantime retaining the modulus with 1 GPa. The addition of CNCfs@CNC hardly affects the glass transition temperature and thermo-mechanical properties of PLA. The dielectric properties of PLA/CNCfs1.0/CNC2.0 blends were maximized at 1000 Hz, reaching a value of 21, which can be attributed to the synergistic effect of multilayer interfacial polarization.

[Murine model of Graves disease induced by thyroid-stimulating hormone receptor gene transfected via liposome].

OBJECTIVE: To compare the efficacy of different expression vectors, target genes, and immunization procedures in transfecting mice via liposome to construct murine model of Graves disease. METHODS: We linked pCDNA3.1(+) and pUBC to full-length human TSHR and TSHR A subunit cDNA to yield four plasmids, which were later injected intramascularly or subcutaneously into female Balb/c mice via liposome. The blood anti-TSHR antibody (TRAb) were determined and the body weight were measured after each immunization. Serum thyroid hormone levels were measured after the animals were sacrificed. RESULTS: In mice immunized with pUBC, no significant variance with control in weight nor serum TRAb concentration was observed. Weight gain in pCDNA3.1(+) group was significantlyly slower than controls (p<0.05), and serum TRAb concentration was also significantly elevated. In pCDNA group, animals immunized with TSHR A subunit (TSHRA subgroup) as the target gene revealed even significantly slower weight gain (p<0.001) and even faster TRAb elevation than those immunized with full length TSHR. Significantly higher FT4 (p=0.023) was observed in TSHRA and TSHR subgroups, which was reversely correlated to weight gain, but no significant difference (p>0.05) in FT3 was observed. Weight gain and TRAb concentration mainly varied in the later period of immunization. CONCLUSIONS: Immunization with pCDNA3.1(+) and TSHR A subunit gene together with higher immunization frequency increases the chance of model induction. Furthermore, FT4 is a better indicator for assessing the thyroid function in this model.

[Two Serum Free Light Chain Detection Systems in the Diagnosis of Multiple Myeloma].

OBJECTIVE: To investigate the comparability of the Freelite, Binding Site, Beckman and N Latex FLC, Siemens in the detection of serum free light chain (sFLC) . METHODS: Fifty newly diagnosed multiple myeloma (MM) patients in Tianjin Institute of Blood Research from November 2019 to February 2020 were enrolled. The two systems (Freelite, Binding Site, Beckman and N Latex FLC, Siemens) were used to detect the sFLC of the samples. Outlier detection was performed by ESD method, methodological comparison and deviation assessment were performed by Passing-Bablok regression and Bland-Altman regression. RESULTS: Both the systems could quantitatively analyze free kappa light chain serum samples and free lambda light chain samples. Freelite, Binding Site, Beckman and N Latex FLC, Siemens free light chain test showed FLC-κ：36.5 (6.5, 194), 40.5 (6.94, 288), FLC-λ: 30.1 (4.3, 170.5), 35.1 (2.28, 526), rFLC (FLC-κ/ FLC-λ) : 0.82 (0.05, 43.25), 1.03 (0.03, 32.04), dFLC (｜FLC-κ- FLC-λ｜) : -5.8 (-161.97, 183.7), 1.1 (-505.1, 279.01), which existed no outliers. There were systematic differences, and the deviation level was not within the clinically acceptable range. CONCLUSION: Both the systems can meet the needs of clinical diagnosis and treatment, but there is a significant deviation between the two systems, the results are not comparable, and should be analyzed separately. In particular, the same system should be selected for monitoring the prognosis of MM.

Thread shape affects the stress distribution of torque force on miniscrews: a finite element analysis.

This study aimed to investigate the effect of miniscrews thread shape on the stress distribution receiving a torque load. Seven thread shapes (S,V1,V2,B1,B2,R1,R2) models were constructed and a 6 Nmm-torque load was applied. The order of maximum equivalent stress (EQV) value was V1 > V2 > B1 > R1 > R2 > B2 > S. The order of maximum displacement of miniscrew (Max DM) value was S > B2 > R1 = V1 > B1 > V2 > R2. Model R2 may be the most appropriate thread shape affording a torque force.

3D-Printed Poly(ε-caprolactone) Scaffold Augmented With Mesenchymal Stem Cells for Total Meniscal Substitution: A 12- and 24-Week Animal Study in a Rabbit Model.

BACKGROUND: Total meniscectomy leads to knee osteoarthritis in the long term. The poly(ε-caprolactone) (PCL) scaffold is a promising material for meniscal tissue regeneration, but cell-free scaffolds result in relatively poor tissue regeneration and lead to joint degeneration. HYPOTHESIS: A novel, 3-dimensional (3D)-printed PCL scaffold augmented with mesenchymal stem cells (MSCs) would offer benefits in meniscal regeneration and cartilage protection. STUDY DESIGN: Controlled laboratory study. METHODS: PCL meniscal scaffolds were 3D printed and seeded with bone marrow-derived MSCs. Seventy-two New Zealand White rabbits were included and were divided into 4 groups: cell-seeded scaffold, cell-free scaffold, sham operation, and total meniscectomy alone. The regeneration of the implanted tissue and the degeneration of articular cartilage were assessed by gross and microscopic (histological and scanning electron microscope) analysis at 12 and 24 weeks postoperatively. The mechanical properties of implants were also evaluated (tensile and compressive testing). RESULTS: Compared with the cell-free group, the cell-seeded scaffold showed notably better gross appearance, with a shiny white color and a smooth surface. Fibrochondrocytes with extracellular collagen type I, II, and III and proteoglycans were found in both seeded and cell-free scaffold implants at 12 and 24 weeks, while the results were significantly better for the cell-seeded group at week 24. Furthermore, the cell-seeded group presented notably lower cartilage degeneration in both femur and tibia compared with the cell-free or meniscectomy group. Both the tensile and compressive properties of the implants in the cell-seeded group were significantly increased compared with those of the cell-free group. CONCLUSION: Seeding MSCs in the PCL scaffold increased its fibrocartilaginous tissue regeneration and mechanical strength, providing a functional replacement to protect articular cartilage from damage after total meniscectomy. CLINICAL RELEVANCE: The study suggests the potential of the novel 3D PCL scaffold augmented with MSCs as an alternative meniscal substitution, although this approach requires further improvement before being used in clinical practice.

Mechanical Properties of Orthodontic Thermoplastics PETG/ PC2858 after Blending.

OBJECTIVE: To characterise and compare the tensile characteristics after multi-proportional blending, to determine the proper blending ratio for new thermoplastic material and to compare its mechanical performance with commercial thermoplastics. METHODS: PETG and PC2858 aggregates were blended in five different ratios. Standard specimens of each ratio were molded and tested to determine their mechanical performance. Then the new material with the proper blending ratio was chosen and compared against commercial thermoplastics. RESULTS: With the increase of PC2858 content, the tensile and impact strength increased but elongation at break decreased. When blending ratio (wt %) was 70/30, the PETG/PC2858 exhibited optimal mechanical properties, with a tensile strength of 63.42 ± 1.67 MPa, and a stress relaxation rate of 0.0080 ± 0.0005 N/s, which exceeded those of Erkodur and Biolon. CONCLUSION: By blending PETG and PC2858 at the weight ratio 70/30, we obtained new thermoplastic material which outperformed commercial products.

Extracellular polymeric substances production kinetics of 13 sludge isolates using wastewater sludge as raw material and its flocculation potential.

The kinetics of batch fermentation of 13 extracellular polymeric substances (EPS) producing bacterial strains (9 Bacillus, 2 Serratia and 2 Yersinia) were carried out using sterilized sludge as a raw material. The most of Bacillus (µ(max): 0.11-0.27 h⁻¹), Serratia (µ(max): 0.23-0.27 h⁻¹) and Yersinia (µ(max): 0.18-0.19 h⁻¹) strains had capability to grow and produce EPS (1.36-2.12 g/L) in the sterilized sludge. In general, EPS production was mixed growth associated for all the bacterial strains cultivated independently. Bacillus sp. 7, Serratia sp. 2 and Yersinia sp. 2 produced higher concentration (1.95-2.12 g/L) of EPS than the other remaining bacterial strains. Protein and carbohydrate contents of EPS remained constant during fermentation. Broth EPS (B-EPS) exhibited high kaolin flocculation activity (≥ 75%) in most of the cases except Bacillus sp. 1, Bacillus sp. 5 and Bacillus sp. 9, respectively. In general, high flocculation activities (FAs) (≥ 75%), were attained using 1.31-1.70 mg B-EPS/g kaolin, 0.45-0.97 mg protein/g kaolin and 0.11-0.21 mg carbohydrates/g kaolin. The study suggests that further systematic exploration is required for optimizing the process of EPS production. EPS produced in the sludge can potentially be used for different water and wastewater treatments.

OsKinesin-13A is an active microtubule depolymerase involved in glume length regulation via affecting cell elongation.

Grain size is an important trait influencing both the yield and quality of rice and its major determinant is glume size. However, how glume size is regulated remains largely unknown. Here, we report the characterization of OsKinesin-13A, which regulates cell elongation and glume length in rice. The mutant of OsKinesin-13A, sar1, displayed length reduction in grains and other organs including internodes, leaves and roots. The grain phenotype in sar1 was directly caused by reduction in glume length, which in turn restricted caryopsis size. Histological results revealed that length decrease in sar1 organs resulted from abnormalities in cell elongation. The orientation of cellulose microfibrils was defective in sar1. Consistently, sar1 showed reduced transverse orientation of cortical microtubules. Further observations demonstrated that microtubule turnover was decreased in sar1. OsKinesin-13A was shown to be an active microtubule depolymerase and mainly distributed on vesicles derived from the Golgi apparatus and destined for the cell surface. Thus, our results suggest that OsKinesin-13A utilizes its microtubule depolymerization activity to promote microtubule turnover, which may not only influence transverse orientation of cortical microtubules but also facilitate vesicle transport from the Golgi apparatus to the cell surface, and thus affects cellulose microfibril orientation and cell elongation.

Finite Element Analysis of Bone Stress around Micro-Implants of Different Diameters and Lengths with Application of a Single or Composite Torque Force.

BACKGROUND: Stress on the bone surrounding dental micro-implants affects implant success. PURPOSE: To compare the stress on the bone surrounding a micro-implant after application of a single force (SF) of 200 g or a composite force (CF) of 200 g and 6 N.mm torque. MATERIALS AND METHODS: Finite element models were developed for micro-implant diameters of 1.2, 1.6, and 2.0 mm, and lengths of 6, 8, 10, and 12 mm and either a SF or CF was applied. The maximum equivalent stress (Max EQS) of the bone surrounding the micro-implant was determined, and the relationships among type of force, diameter, and length were evaluated. RESULTS: The Max EQS of the CF exceeded that of the SF (P< 0.05). The effect of force on stress was related to implant diameter, but not to implant length. The larger CF led to greater instability of the micro-implant and the effect was most pronounced at an implant diameter of 1.2 mm. The use of implant diameters of 1.6 mm and 2.0 mm produced no significant difference in implant stability when either a CF or SF was applied. CONCLUSION: When considering the use of an implant to perform three-dimensional control on the teeth, the implant diameter chosen should be > 1.2 mm.

[Influence of the diameter and length of the mini-implant on the primary stability after loading with composite forces].

OBJECTIVE: To investigate the influence of the diameter and length of the mini-implant on the primary stability after loading with composite forces (CF) which contained torque and horizontal forces (HF). METHODS: Ninety-six finite element models were established by the combination of mini-implant and bone, diameters (1.2 mm, 1.6 mm, 2.0 mm) and length (6 mm, 8 mm, 10 mm, 12 mm). There were 12 sizes, each size corresponded with 8 models. Group HF (each size n = 4) was loaded with 1.96 N horizontal force and Group CF (each size n = 4) was loaded with composite force which contained 6 N·mm torque and 1.96 N horizontal force. The maximum displacement of mini-implant with different force directions, implant diameters and lengths were evaluated. RESULTS: The effect of force direction on the displacement related to diameter of mini-implant. The maximum displacement under load with HF respectively was changed with the changing of diameter[1.2 mm: (7.71 ± 0.49) µm; 1.6 mm: (3.94 ± 0.31) µm; 2.0 mm: (2.32 ± 0.43) µm], which were smaller than the maximum displacement of Group CF [1.2 mm: (9.22 ± 0.63) µm; 1.6 mm: (4.62 ± 0.52) µm; 2.0 mm: (2.69 ± 0.49) µm] (P < 0.05). When diameter was 1.2 mm, the difference of the maximum displacement [(1.61 ± 0.22) µm] between Group HF and CF was more obvious than that when the diameter was 1.6 mm or 2.0 mm [(0.64 ± 0.12), (0.49 ± 0.06) µm] (P < 0.05). CONCLUSIONS: The composite force had unfavorable effect on the primary stability of the mini-implant. The diameter of the mini-implant had better be larger than 1.2 mm when the composite forces were applied.

Promotion of peripheral nerve regeneration of a peptide compound hydrogel scaffold.

BACKGROUND: Peripheral nerve injury is a common trauma, but presents a significant challenge to the clinic. Silk-based materials have recently become an important biomaterial for tissue engineering applications due to silk's biocompatibility and impressive mechanical and degradative properties. In the present study, a silk fibroin peptide (SF16) was designed and used as a component of the hydrogel scaffold for the repair of peripheral nerve injury. METHODS: The SF16 peptide's structure was characterized using spectrophotometry and atomic force microscopy, and the SF16 hydrogel was analyzed using scanning electron microscopy. The effects of the SF16 hydrogel on the viability and growth of live cells was first assessed in vitro, on PC12 cells. The in vivo test model involved the repair of a nerve gap with tubular nerve guides, through which it was possible to identify if the SF16 hydrogel would have the potential to enhance nerve regeneration. In this model physiological saline was set as the negative control, and collagen as the positive control. Walking track analysis and electrophysiological methods were used to evaluate the functional recovery of the nerve at 4 and 8 weeks after surgery. RESULTS: Analysis of the SF16 peptide's characteristics indicated that it consisted of a well-defined secondary structure and exhibited self-assembly. Results of scanning electron microscopy showed that the peptide based hydrogel may represent a porous scaffold that is viable for repair of peripheral nerve injury. Analysis of cell culture also supported that the hydrogel was an effective matrix to maintain the viability, morphology and proliferation of PC12 cells. Electrophysiology demonstrated that the use of the hydrogel scaffold (SF16 or collagen) resulted in a significant improvement in amplitude recovery in the in vivo model compared to physiological saline. Moreover, nerve cells in the SF16 hydrogel group displayed greater axon density, larger average axon diameter and thicker myelin compared to those of the group that received physiological saline. CONCLUSION: The SF16 hydrogel scaffold may promote excellent axonal regeneration and functional recovery after peripheral nerve injury, and the SF16 peptide may be a candidate for nerve tissue engineering applications.

[A study on the influence of fluid shear stress on the expression of COX-2 in HPDLF].

PURPOSE: To utilize the fluid shear stress to simulate occlusion trauma in vitro. Different density of FN was given to HPDLF and the amount of COX-2 mRNA of HPDLF was measured at different time. METHODS: Young healthy permanent teeth which were extracted for orthodontic treatment were collected. The HPDLF was primarily cultured via the method for tissue block. The third generation cells were taken as the study objects. There were two groups in this study. Group A were cultured with the fluid shear stress given by a special swing bed(35r/min). Group B were cultured quietly. Different density of FN (0,20,40,60microg/ml)was added into Group A and B. The cells were cultured for 6 and 12 hours without serum. RESULTS: After 24 hours, 80% tissue block anchoraged. After 7-10 days,there were cells moving from the tissue block,After about 14 days, the cell overgrew the culture flask.Immuocytochemistry showed that anti- filamin was positive while anti- ceratin was negative. The expression of COX-2 mRNA was positive after 6 hours in group A,and the amount of the expression decreased with the increase of the amount of FN . The expression of COX-2 mRNA after 12 hours in group A was higher than that after 6 hours. The result of electrophoresis for group B was negative. The electrophoresis optical density of beta-actin amplification fragment was uniform. CONCLUSIONS: The fluid shear stress can revoke the inflammatory reaction of HPDLF. Human plasma FN can decreased the expression of COX-2 mRNA of HPDLF,which is dose and time dependent.

[Expression of HOX C13 in odontogenic tumors].

PURPOSE: To study the expression of HOXC13 mRNA in odontogenic tumors. METHODS: HOXC13 mRNA was detected in 47 cases of ameloblastoma (AB), 3 cases of calcifying cystic odontogenic tumor (CCOT), 3 cases of ameloblastic fibroma (AF), 10 cases of keratocystic odontogenic tumor (KCOT) and 2 cases of calcifying epithelial odontogenic tumor (CEOT) by in situ hybridization, and 7 cases of normal oral mucosa were selected as control. SPSS10.0 software package was used for chi(2) test. RESULTS: HOXC13 mRNA was positively expressed in all odontogenic epithelium except AF. The positive ratios were 97.9% in AB, 100% in CCOT, 100% in CEOT, 70.0% in KCOT epithelium and 42.9% in the normal oral mucosa. There was significant difference among AB, KCOT and normal mucosa (chi(2)=21.665, P<0.001). CONCLUSIONS: The genesis and development of odontogenic tumors are related to the high expression of HOXC13. The expression of HOXC13 mRNA in the odontogenic lesions has heterogeneity.

[Effect of activated sludge properties on short-term membrane fouling in submerged membrane bioreactor based on statistical analysis].

The influence of activated sludge properties on membrane fouling was investigated using statistical method. The results show that extracelluler polymeric substances (EPS), soluble microbial products (SMP), suspended solids in the supernatant (SSs), dynamic viscosity (micro), relative hydrophobicity (RH) and Zeta potential all have a significant influence on membrane permeability during microfiltration of activated sludge wastewater. The pearson's correlation coefficient (r(p)) for linear correlations between membrane fouling resistance and these sludge properties are 0.898, 0.712, 0.810, 0.691, 0.837, -0.881, respectively. The statistical results also show that SMP, micro, SSs, Zeta potential, and RH are mostly determined by EPS, indicating that EPS is the main and essential factor affecting membrane fouling in activated sludge properties. The pearson's correlation coefficient (r(p)) for linear correlations between total EPS and other sludge properties are 0.682, 0.633, 0.783, -0.953, 0.877, respectively. EPS should be controlled in the operation of membrane bioreactor to achieve a suitable permeation.