A DE1 BINDING FACTOR 1-GLABRA2 module regulates rhamnogalacturonan I biosynthesis in Arabidopsis seed coat mucilage.

The mucilage surrounding hydrated Arabidopsis thaliana seeds is a specialized extracellular matrix composed mainly of the pectic polysaccharide rhamnogalacturonan I (RG-I). Although, several genes responsible for RG-I biosynthesis have been identified, the transcriptional regulatory mechanisms controlling RG-I production remain largely unknown. Here we report that the trihelix transcription factor DE1 BINDING FACTOR 1 (DF1) is a key regulator of mucilage RG-I biosynthesis. RG-I biosynthesis is significantly reduced in loss-of-function mutants of DF1. DF1 physically interacts with GLABRA2 (GL2) and both proteins transcriptionally regulate the expression of the RG-I biosynthesis genes MUCILAGE MODIFIED 4 (MUM4) and GALACTURONOSYLTRANSFERASE-LIKE5 (GATL5). Through chromatin immunoprecipitation-quantitative PCR and transcriptional activation assays, we uncover a cooperative mechanism of the DF1-GL2 module in activating MUM4 and GATL5 expression, in which DF1 binds to the promoters of MUM4 and GATL5 through interacting with GL2 and facilitates the transcriptional activity of GL2. The expression of DF1 and GL2 is directly regulated by TRANSPARENT TESTA GLABRA2 (TTG2) and, in turn, DF1 directly represses the expression of TTG2. Taken together, our data reveal that the transcriptional regulation of mucilage RG-I biosynthesis involves a regulatory module, comprising DF1, GL2, and TTG2.

Identification and Analysis of the Mechanism of Stem Mechanical Strength Enhancement for Maize Inbred Lines QY1.

Enhancing stalk strength is a crucial strategy to reduce lodging. We identified a maize inbred line, QY1, with superior stalk mechanical strength. Comprehensive analyses of the microstructure, cell wall composition, and transcriptome of QY1 were performed to elucidate the underlying factors contributing to its increased strength. Notably, both the vascular bundle area and the thickness of the sclerenchyma cell walls in QY1 were significantly increased. Furthermore, analyses of cell wall components revealed a significant increase in cellulose content and a notable reduction in lignin content. RNA sequencing (RNA-seq) revealed changes in the expression of numerous genes involved in cell wall synthesis and modification, especially those encoding pectin methylesterase (PME). Variations in PME activity and the degree of methylesterification were noted. Additionally, glycolytic efficiency in QY1 was significantly enhanced. These findings indicate that QY1 could be a valuable resource for the development of maize varieties with enhanced stalk mechanical strength and for biofuel production.

PagERF81 regulates lignin biosynthesis and xylem cell differentiation in poplar.

Lignin is a major component of plant cell walls and is essential for plant growth and development. Lignin biosynthesis is controlled by a hierarchical regulatory network involving multiple transcription factors. In this study, we showed that the gene encoding an APETALA 2/ethylene-responsive element binding factor (AP2/ERF) transcription factor, PagERF81, from poplar 84 K (Populus alba × P. glandulosa) is highly expressed in expanding secondary xylem cells. Two independent homozygous Pagerf81 mutant lines created by gene editing, produced significantly more but smaller vessel cells and longer fiber cells with more lignin in cell walls, while PagERF81 overexpression lines had less lignin, compared to non-transgenic controls. Transcriptome and reverse transcription quantitative PCR data revealed that multiple lignin biosynthesis genes including Cinnamoyl CoA reductase 1 (PagCCR1), Cinnamyl alcohol dehydrogenase 6 (PagCAD6), and 4-Coumarate-CoA ligase-like 9 (Pag4CLL9) were up-regulated in Pagerf81 mutants, but down-regulated in PagERF81 overexpression lines. In addition, a transient transactivation assay revealed that PagERF81 repressed the transcription of these three genes. Furthermore, yeast one hybrid and electrophoretic mobility shift assays showed that PagERF81 directly bound to a GCC sequence in the PagCCR1 promoter. No known vessel or fiber cell differentiation related genes were differentially expressed, so the smaller vessel cells and longer fiber cells observed in the Pagerf81 lines might be caused by abnormal lignin deposition in the secondary cell walls. This study provides insight into the regulation of lignin biosynthesis, and a molecular tool to engineer wood with high lignin content, which would contribute to the lignin-related chemical industry and carbon sequestration.

Preparation and Self-Cleaning Performance of Carbon-Based Superhydrophobic Coatings Based on Non-Fluorine and Non-Toxic Corn Straw.

Recently, superhydrophobic surfaces with self-cleaning ability have attracted broad research interest due to their huge potential in daily lives and industrial applications, but the use of fluorinate, toxic organic compounds, and expensive feedstocks make superhydrophobic materials a great challenge in practical application. In this study, we present a facile dip-coating strategy to prepare superhydrophobic coatings with self-cleaning properties based on a non-fluorine and non-toxic system by using eco-friendly corn straw as raw material. During this process, aromatic carbon particles with rough hierarchical structures were prepared firstly via a simple fast pyrolysis process, followed by modification with polydimethylsiloxane (PDMS) in absolute ethanol solvent to decrease the surface free energy. Research shows these natural straw-derived carbons display a microstructure of several protrusions which is similar to the lotus leave's and the resulted coatings exhibit an outstanding superhydrophobic property with a static water contact angle (WCA) of 151.67 ± 1.36 degrees. In addition, the as-prepared coatings possessed excellent self-cleaning performance: no contaminations were observed on the surfaces after examining with sludge, calcimine, water, and common liquids such as tea, milk, soybean milk as well as ink, which have a broad range of potential application in the field of antifouling, waterproofing, and anticorrosive.

[Clinical features of osteonecrosis of jaws after bisphosphonates therapy for bone metastasis of breast cancer].

OBJECTIVE: To understand the clinical features of osteonecrosis of the jaw after bisphosphonates use for therapy of breast cancer patients with bone metastasis. METHODS: The cases diagnosed as bisphosphonates-related osteonecrosis of the jaws (BRONJ) were retrospectively analyzed from January 2011 to August 2015 in the Peking University School and Hospital of Stomatology, and those breast cancer patients with bone metastasis were selected. The clinical symptoms, imaging characteristics and treatment results were summarized. RESULTS: A total of 14 cases of breast cancer patients with bone metastasis were selected, with an average age of 60.21 years. The average time of suffering from breast cancer was 9.77 years, and the average time of bone metastasis and bisphosphonates drugs use was 5.67 and 3.29 years individually. There was no patient with systemic application history of hormone therapy, and no history of diabetes. There were 9 patients with tooth extractions history, and the mean time of bone necrosis symptoms was 8.58 months. There were 10 cases with bone necrosis occurring on mandible, 3 cases on maxilla, and one case with both upper and lower jaws involved. Among the 10 patients with surgical treatment, there were 3 cases cured, and 6 cases improved. However, the clinical symptoms of 2 cases with conservative treatment were significantly aggravated. CONCLUSION: The medication time between the bisphosphonates use beginning and the occurrence of BRONJ is relatively long. The history of diabetes and long-time hormone use did not exist in this group. Tooth extraction itself does not determine the severity of BRONJ. Mandible is the most common site involved by BRONJ. Surgical treatment can alleviate the clinical symptoms of BRONJ with breast cancer to some extent.

Metabolic engineering of 2-phenylethanol pathway producing fragrance chemical and reducing lignin in Arabidopsis.

KEY MESSAGE: Two 2-phenylethanol biosynthetic pathways were constructed into Arabidopsis ; 2-phenylethanol biosynthesis led to reduced rate of lignin biosynthesis and increased cellulose-to-glucose conversion in the transgenic plants. Lignin is the second most abundant biopolymer on the planet with importance for various agro-industrial activities. The presence of lignin in cell walls, however, impedes biofuel production from lignocellulosic biomass. The phenylpropanoid pathway is responsible for the biosynthesis of lignin and other phenolic metabolites such as 2-phenylethanol. As one of the most used fragrance chemicals, 2-phenylethanol is synthesized in plants from L-phenylalanine which is the first specific intermediate towards lignin biosynthesis. Thus, it is interesting to prove the concept that the phenylpropanoid pathway can be modulated for reduction of lignin as well as production of natural value-added compounds. Here we conferred two 2-phenylethanol biosynthetic pathways constructed from plants and Saccharomyces cerevisiae into Arabidopsis. As anticipated, 2-phenylethanol was accumulated in transgenic plants. Moreover, the transformants showed 12-14% reduction in lignin content and 9-13% increase in cellulose content. Consequently, the glucose yield from cell wall hydrolysis was increased from 37.4% in wild type to 49.9-52.1% in transgenic plants with hot water pretreatment. The transgenic plants had normal development and even enhanced growth relative to the wild type. Our results indicate that the shunt of L-phenylalanine flux to the artificially constructed 2-phenylethanol biosynthetic pathway most likely reduced the rate of lignin biosynthesis in Arabidopsis.

Poplar PdC3H17 and PdC3H18 are direct targets of PdMYB3 and PdMYB21, and positively regulate secondary wall formation in Arabidopsis and poplar.

Wood biomass is mainly made of secondary cell walls, whose formation is controlled by a multilevel network. The tandem CCCH zinc finger (TZF) proteins involved in plant secondary wall formation are poorly understood. Two TZF genes, PdC3H17 and PdC3H18, were isolated from Populus deltoides and functionally characterized in Escherichia coli, tobacco, Arabidopsis and poplar. PdC3H17 and PdC3H18 are predominantly expressed in cells of developing wood, and the proteins they encode are targeted to cytoplasmic foci. Transcriptional activation assays showed that PdMYB2/3/20/21 individually activated the PdC3H17 and PdC3H18 promoters, but PdMYB3/21 were most significant. Electrophoretic mobility shift assays revealed that PdMYB3/21 bound directly to the PdC3H17/18 promoters. Overexpression of PdC3H17/18 in poplar increased secondary xylem width and secondary wall thickening in stems, whereas dominant repressors of them had the opposite effects on these traits. Similar alteration in secondary wall thickening was observed in their transgenic Arabidopsis plants. qRT-PCR results showed that PdC3H17/18 regulated the expression of cellulose, xylan and lignin biosynthetic genes, and several wood-associated MYB genes. These results demonstrate that PdC3H17 and PdC3H18 are the targets of PdMYB3 and PdMYB21 and are an additional two components in the regulatory network of secondary xylem formation in poplar.

Clinicopathological study of malignant peripheral nerve sheath tumors in the head and neck: Case reports and review of literature.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a rare and aggressive soft tissue sarcoma that poses a major diagnostic and therapeutic challenge. CASE SUMMARY: We retrospectively reviewed patients with head and neck MPNSTs treated in our hospital from 2000 to 2021. The clinical features, pathological manifestations, treatments, and prognoses were summarized. We also reviewed the literature, focusing on MPNST in the mandible and maxilla. The study population consisted of five women and five men aged 22-75 years (mean age, 49 years). Of the 10 patients, 7 were initial cases and 3 were recurrent cases. All lesions were sporadic. The most common site was the mandible. The most frequently encountered symptoms were a progressive mass and local swelling. Complete or partial loss of trimethylation at lysine 27 of histone H3 (H3K27me3) was evident on staining in four of nine cases (one case was excluded due to lack of tissue for evaluation of loss of H3K27me3). The 2- and 5-year disease-specific survival rates were 86% and 43%, respectively. The average survival time was 64 mo. CONCLUSION: MPNST is a highly malignant tumor with a poor prognosis, prone to a high risk of recurrence and distant metastasis. Complete surgical resection is the main treatment.

The application of an intraoral banana peel suturing model in surgical training of dental students.

OBJECTIVES: This study investigated the application of an intraoral banana peel suturing model in helping students to acquire intraoral surgical techniques. METHODS: This is a self-control study conducted from January 2021 to March 2021. An intraoral banana peel suturing model was implemented to provide oral suture experience for undergraduates majoring in stomatology. The sutures students placed in the model were photographed and evaluated blindly by a professional team using an established scoring system. Training scores were recorded before (training 1) and after 2 months of training (training 2). Linear regression was used to examine factors related to the scores. Suturing training was conducted in the School and Hospital of Stomatology at Peking University. A total of eighty-two students in Peking University School and Hospital of Stomatology were in their fourth pre-clinical year and followed a workshop on surgical sutures according to the curriculum. All students who should take this course were included, and the response rate was 100%. RESULTS: The mean training 2 score (23.04 ± 3.83) was higher than the mean training 1 score (13.94 ± 3.15). The training 1 score was not significantly correlated with any of the students' general characteristics. The training 2 score was correlated with the training 1 score and the cumulative duration of practice outside of class. CONCLUSION: The intraoral banana peel suturing model can be used for suture training, and dental students' suture ability was improved after using the banana peel for suture practice.

A new mammal from the Lower Cretaceous Jehol Biota and implications for eutherian evolution.

Here we report on a new Early Cretaceous eutherian represented by a partial skeleton from the Jiufotang Formation at Sihedang site, Lingyuan City, Liaoning Province that fills a crucial gap between the earliest eutherians from the Yixian Formation and later Cretaceous eutherians. The new specimen reveals, to our knowledge for the first time in eutherians, that the Meckelian cartilage was ossified but reduced in size, confirming a complete detachment of the middle ear from the lower jaw. Seven hyoid elements, including paired stylohyals, epihyals and thyrohyals and the single basihyal are preserved. For the inner ear the ossified primary lamina, base of the secondary lamina, ossified cochlear ganglion and secondary crus commune are present and the cochlear canal is coiled through 360°. In addition, plesiomorphic features of the dentition include weak conules, lack of pre- and post-cingula and less expanded protocones on the upper molars and height differential between the trigonid and talonid, a large protoconid and a small paraconid on the lower molars. The new taxon displays an alternating pattern of tooth replacement with P3 being the last upper premolar to erupt similar to the basal eutherian Juramaia. Parsimony analysis places the new taxon with Montanalestes, Sinodelphys and Ambolestes as a sister group to other eutherians. This article is part of the theme issue 'The impact of Chinese palaeontology on evolutionary research'.

High-dose-rate interstitial brachytherapy vs external beam radiation for the treatment of complex keloids.

Postoperative external beam radiation therapy (EBRT) with superficial X-rays or electrons and high-dose-rate brachytherapy (HDR BT) are both viable options for managing keloid scars. However, complex keloid scars are especially challenging to manage. We aim to compare the benefit and challenges between interstitial HDR BT and electron EBRT in treating the complex keloids. Three patients with 7 complex keloids: 3 jaw lines, 1 postauricular, 1 posterior neck, and 2 chest walls are included in this study. All patients are treated to 6 Gy x 3 fractions with HDR BT using the flexible interstitial catheters, and electron EBRT plans were created retrospectively for dosimetric comparison. The average D90 is 21.8 ± 8.3 Gy (1 SD) (121%) and 16.9 ± 1.9 Gy (1SD) (94%) in HDR and EBRT plans, respectively. The average treatment time was 7 minutes per patient (range: 6 - 8.5 minutes) for the HDR BT. Dosimetric comparison reveals that HDR plans provide superior coverage to the keloid scars than the EBRT plans. Clinical workflow is streamlined with HDR procedures. The cosmetic outcome with the interstitial HDR BT is satisfactory.

Mechanism of transverse fracture of the skull base caused by blunt force to the mandible.

Transverse fracture of the skull base is common both in the crushing of temporal regions of the skull and in the case of force acting on one temporal region. However, the mechanism of transverse skull base fracture caused by maxillofacial force has not been fully clarified. To provide an injury identification basis for forensic pathologists and clinicians, this paper combines accident reconstruction and finite element analysis methods to study the injury mechanism of an incomplete transverse fracture of skull base after the injured individual's mandible was subjected to violence in a traffic accident. The results show that after the injured individual's mandible was subjected to violence, forces in the direction of the left mandibular fossa and the right mandibular fossa were generated, creating the component forces. The combination of the two forces can produce a crushing effect toward the center of the skull base, as if the left and right temporal regions are being crushed, and the stress is concentrated at the joint of the mandible, the middle cranial fossa and the hypophyseal fossa. When the stress exceeds a certain limit, it will cause a transverse fracture of the skull base.

Local anesthesia in oral and maxillofacial surgery: A review of current opinion.

Local anesthesia (LA) is the most important pain management process in oral and maxillofacial surgery. Safe and effective LA not only enable patients to obtain high-quality treatment, but also relieve the anxiety of patients when they come to the clinic. The choices of local anesthetic and injection methods determine the success of LA to a great extent. At present, in most countries or regions, common local anesthetics used in oral and maxillofacial surgery belong to amides and they are injected into patients' body mainly through block or infiltration anesthesia. In addition, the operators' technique level, patient's subjective psychology and anatomical variation of maxillofacial structure also have a strong influence on LA in dental clinic. Due to the existence of above factors, the worldwide success rates of LA in oral and maxillofacial surgery is very different. There are no specific LA methods that ensure 100% successful LA rates. Fortunately, the development of new local anesthetic and injection technology are providing us with new ideas to solve this problem. This review mainly report the new research progress on LA in oral and maxillofacial surgery in recent decades and help clinicians with dental LA operation.

Neurotrophic effects of dental pulp stem cells in repair of peripheral nerve after crush injury.

BACKGROUND: Nerve diseases and injuries, which are usually accompanied by motor or sensory dysfunction and disorder, impose a heavy burden upon patients and greatly reduce their quality of life. Dental pulp stem cells (DPSCs), derived from the neural crest, have many characteristics that are similar to those of neural cells, indicating that they can be an ideal source for neural repair. AIM: To explore the potential roles and molecular mechanisms of DPSCs in crushed nerve recovery. METHODS: DPSCs were isolated, cultured, and identified by multilineage differentiation and flow cytometry. Western blot and immunofluorescent staining were applied to analyze the expression levels of neurotrophic proteins in DPSCs after neural induction. Then, we collected the secretions of DPSCs. We analyzed their effects on RSC96 cell proliferation and migration by CCK8 and transwell assays. Finally, we generated a sciatic nerve crush injury model in vivo and used the sciatic function index, walking track analysis, muscle weight, and hematoxylin & eosin (H&E) staining to further evaluate the nerve repair ability of DPSCs. RESULTS: DPSCs highly expressed several specific neural markers, including GFAP, S100, Nestin, P75, and NF200, and were inclined toward neural differentiation. Furthermore, neural-induced DPSCs (N-DPSCs) could express neurotrophic factors, including NGF, BDNF, and GDNF. The secretions of N-DPSCs could enhance the proliferation and migration of Schwann cells. In vivo, both DPSC and N-DPSC implants alleviated gastrocnemius muscle atrophy. However, in terms of anatomy and motor function, as shown by H&E staining, immunofluorescent staining, and walking track analyses, the repair effects of N-DPSCs were more sustained, potent, and effective than those of DPSCs and the controls. CONCLUSION: In summary, this study demonstrated that DPSCs are inclined to differentiate into neural cells. N-DPSCs express neurotrophic proteins that could enhance the proliferation and migration of SCs. Furthermore, our results suggested that N-DPSCs could help crushed nerves with functional recovery and anatomical repair in vivo. Thus, DPSCs or N-DPSCs could be a promising therapeutic cell source for peripheral nerve repair and regeneration.

Enhance wastewater biological treatment through the bacteria induced graphene oxide hydrogel.

The interaction between bacteria and graphene-family materials like pristine graphene, graphene oxide (GO) and reduced graphene oxide (rGO) is such an elusive issue that its implication in environmental biotechnology is unclear. Herein, two kinds of self-assembled bio-rGO-hydrogels (BGHs) were prepared by cultivating specific Shewanella sp. strains with GO solution for the first time. The microscopic examination by SEM, TEM and CLSM indicated a porous 3D structure of BGHs, in which live bacteria firmly anchored and extracellular polymeric substances (EPS) abundantly distributed. Spectra of XRD, FTIR, XPS and Raman further proved that GO was reduced to rGO by bacteria along with the gelation process, which suggests a potential green technique to produce graphene. Based on the characterization results, four mechanisms for the BGH formation were proposed, i.e., stacking, bridging, rolling and cross-linking of rGO sheets, through the synergistic effect of activities and EPS from special bacteria. More importantly, the BGHs obtained in this study were found able to achieve unique cleanup performance that the counterpart free bacteria could not fulfill, as exemplified in Congo red decolorization and Cr(VI) bioreduction. These findings therefore enlighten a prospective application of graphene materials for the biological treatment of wastewaters in the future.

Mitochondrial Molecular Abnormalities Revealed by Proteomic Analysis of Hippocampal Organelles of Mice Triple Transgenic for Alzheimer Disease.

Mitochondrial dysfunction is implicated in the pathogenesis of Alzheimer's disease (AD). However, the precise mitochondrial molecular deficits in AD remain poorly understood. Mitochondrial and nuclear proteomic analysis in mature male triple transgenic AD mice (PS1M146V/APPSwe/TauP301L) by two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled with MALDI-TOF-MS/MS, bio-informatics analysis and immunofluorescent staining were performed in this study. In addition to impaired spatial memory impairment and intracellular accumulation of amyloid 1-42 (Aß1-42) in the 3xTg-AD mice, a well-accepted mouse model of the human disease, we also found significantly increased DNA oxidative damage in entorhinal cortex, hippocampal CA1, CA3 and dental gyrus (DG), as evidenced by the positive staining of 8-hydroxyguanosine, a biomarker of mild cognitive impairment early in AD. We identified significant differences in 27 hippocampal mitochondrial proteins (11 increased and 16 decreased), and 37 hippocampal nuclear proteins (12 increased and 25 decreased) in 3xTg-AD mice compared with the wild-type (WT) mice. Differentially expressed mitochondrial and nuclear proteins were mainly involved in energy metabolism (>55%), synapses, DNA damage, apoptosis and oxidative stress. Two proteins were differentially expressed in both hippocampal mitochondria and nuclei, namely electron transport chain (ETC)-related protein ATP synthase subunit d (ATP5H) was significantly decreased, and apoptosis-related dynamin-1 (DYN1), a pre-synaptic and mitochondrial division-regulated protein that was significantly increased. In sum, perturbations of hippocampus mitochondrial energy metabolism-related proteins responsible for ATP generation via oxidation phosphorylation (OXPHOS), especially nuclear-encoded OXPHOS proteins, correlated with the amyloid-associated cognitive deficits of this murine AD model. The molecular changes in respiratory chain-related proteins and DYN1 may represent novel biomarkers of AD.

Aspartic acid racemization in dentin of the third molar for age estimation of the Chaoshan population in South China.

Aspartic acid racemization in teeth has been increasingly used to estimate chronological age with a considerably high accuracy in forensic practice. The Chaoshan population in South China is relatively isolated in geography, and has specific lifestyle and dietary inhibits. It is still unknown whether this method is suitable for this population. The aim of this study was to analyze the relationship between chronological age and the d/l aspartic acid ratio in dentin in the third molar tooth of the Chaoshan population. Fifty-eight non-carious third molar teeth (31 mandibles and 27 maxillae), from 58 living individuals of known age (24 males and 34 females), were retrieved. Dentin was extracted from these teeth. The d- and l-aspartic acids in dentins were separated and detected by high performance liquid chromatography (HPLC). Linear regression was performed between the d/l aspartic acid ratio of dentins and chronological age. Results showed that the correlation coefficient (r) was 0.969, and the mean absolute error (MAE) was 2.19 years, its standard deviation (SD) was ±1.53 years, indicating excellent correlation. There was no significant difference in racemization rates of dentin between sexes (P=0.113, F=2.6), or between mandibles and maxillae (P=0.964, F=0.000). Results indicate that the ratio of the d and l forms of aspartic acid of dentins, in the third molar, is closely correlated with chronological age, special lifestyle do no obviously affect the accuracy of the age estimations by aspartic acid racemization of the dentin in the third molar and that aspartic acid racemization in the third molar dentin can be used as an accurate method to estimate chronological age in the Chaoshan population in South China.

[Determinants of long-term survival in 38 patients with carcinoma of ampulla of Vater treated by local resection].

OBJECTIVE: To investigate determinants of long-term survival for carcinoma of ampulla of Vater treated by local resection. METHODS: The clinical and pathological data of 38 such patients treated by local resection from 1983 to 2003 were retrospectively analyzed. According to UICC staging system, there were T1 30, T2 7 and T3 1. Lymph nodes were involved in 4 during operation which was present in primary lesions larger than 2 cm across. All patients were treated by local resection. At first, external palpation was carried out to ascertain accessibility. Then with the duodenum opened, direct exploration was carried out. On deciding for resection, the common bile duct was probe explored which guided the circumferential ring resection 1 cm, away from the tumor, including all layers of duodenum, ampula and partial bile and terminal pancreatic ducts and the posterial wall of duodenum was completed in steps. Meticulous care was taken not to suture the pancreatic duct and endotheliation was ensured at the mouth of common bile duct and duodenum. The basal tissue was frozen sectioned to ensure negative stumps. The gall bladder of 6 patients was also resected. SPSS 10.0 software was used in data processing, log-rank test used in univariate analysis and Cox equation for multivariate analysis and Kaplan-Meirer method for the survival rates. RESULTS: Thirty-eight patients received local resection giving an operative mortality of 0% and morbidity of 13.2%. The 1-, 5- and 10-year survival rate was 83.5%, 51.4%, and 38.9%, respectively, with a median survival of 3.35 years. Up to now, 13 patients have survived for more than five years and 2 patients beyond ten years. The tumour size, tumour grading, lymph node status and UICC stage were significant prognostic factors in univariate analysis. However, only lymph node status was a statistically independent predictor of prognosis in multivariate analysis. CONCLUSION: Local excision is safe giving low morbidity and good survival in carefully selected cases. Preferably it is indicated only in high risk patients with a pT1 and well differentiated ampullary cancer smaller than 1 cm in diameter.

Preparation and characterization of laser cladding wollastonite derived bioceramic coating on titanium alloy.

The bioceramic coating is fabricated on titanium alloy (Ti6Al4V) by laser cladding the preplaced wollastonite (CaSiO3) powders. The coating on Ti6Al4V is characterized by x-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy, and attenuated total reflection Fourier-transform infrared. The interface bonding strength is measured using the stretching method using an RGD-5-type electronic tensile machine. The microhardness distribution of the cross-section is determined using an indentation test. The in vitro bioactivity of the coating on Ti6Al4V is evaluated using the in vitro simulated body fluid (SBF) immersion test. The microstructure of the laser cladding sample is affected by the process parameters. The coating surface is coarse, accidented, and microporous. The cross-section microstructure of the ceramic layer from the bottom to the top gradually changes from cellular crystal, fine cellular-dendrite structure to underdeveloped dendrite crystal. The coating on Ti6Al4V is composed of CaTiO3, CaO, α-Ca2SiO4, SiO2, and TiO2. After soaking in the SBF solution, the calcium phosphate layer is formed on the coating surface.

Bone morphogenetic protein-transduced human fibroblasts convert to osteoblasts and form bone in vivo.

Experimental cell or ex vivo gene therapy for localized bone formation typically uses osteoprogenitor cells propagated from periosteum or bone marrow. Both require bone or marrow biopsies to obtain cells. We have demonstrated that implantation of gingival or dermal fibroblasts transduced with BMP ex vivo, using a recombinant adenovirus (AdCMVBMP) attached to porous biodegradable scaffolds, form bone in vivo. Here we show that BMP-7-transduced fibroblasts suspended in injectable thermoset hydrogels form complete ossicles on subcutaneous injection and repair segmental defects in rat femurs. Bone formation was preceded by an intermediate cartilage stage. To determine the fate of the implanted transduced cells, thermoset hydrogel suspensions of ex vivo BMP-7-transduced or nontransduced fibroblasts were placed in diffusion chambers and implanted to allow development in vivo without direct contact with host cells. Only the BMP-transduced fibroblasts formed bone within the diffusion chambers in vivo, revealing that BMP transduction induces osteoblastic conversion of these cells.