Orthokeratinized odontogenic cysts: A clinicopathologic study of 159 cases and molecular evidence for the absence of PTCH1 mutations.

BACKGROUND: Orthokeratinized odontogenic cyst (OOC), a newly designated entity of odontogenic cysts, is an intraosseous jaw cyst that is entirely or predominantly lined by orthokeratinized squamous epithelium. The aim of this study was to report a large series of OOC to substantiate its clinicopathologic profiles and to investigate PTCH1 mutations in OOCs. METHOD: The clinicopathologic features of 167 OOCs from 159 patients were analyzed and the immunohistochemical expression of markers related to cell differentiation and proliferation was evaluated. Furthermore, PTCH1 mutations were analyzed in 14 fresh samples of OOC. RESULTS: OOCs occurred mostly in the third and fourth decades (60.4%) with a male predilection (66.7%). The lesions developed more often in the mandible than maxilla, primarily in the posterior mandible and ramus. Eight patients (5.0%) showed multiple locations of either bilateral posterior mandible (n = 6) or both the maxilla and mandible. Radiographically, the majority of OOCs (91.2%) showed a well-demarcated, unilocular radiolucency with 14 multilocular cases (8.8%). A follow-up of 131 patients (123 treated by enucleation with or without marsupialization and eight by peripheral ostectomy) revealed no recurrence during an average period of 4.56 years after surgery. Immunohistochemistry indicated lower proliferative activity and a varying epithelial differentiation pattern in OOC compared with odontogenic keratocysts (OKC). No PTCH1 mutation was detected, except for three known single nucleotide polymorphisms. CONCLUSION: The clinicopathological and molecular differences between OOC and OKC justified their separation, and unlike OKCs, OOCs did not harbor PTCH1 mutations, suggesting different pathogenesis underlying these two jaw cysts.

An Abdominal Registration Technology for Integration of Nanomaterial Imaging-Aided Diagnosis and Treatment.

Image registration technology is a key technology used in the process of nanomaterial imaging-aided diagnosis and targeted therapy effect monitoring for abdominal diseases. Recently, the deep-learning based methods have been increasingly used for large-scale medical image registration, because their iteration is much less than those of traditional ones. In this paper, a coarse-to-fine unsupervised learning-based three-dimensional (3D) abdominal CT image registration method is presented. Firstly, an affine transformation was used as an initial step to deal with large deformation between two images. Secondly, an unsupervised total loss function containing similarity, smoothness, and topology preservation measures was proposed to achieve better registration performances during convolutional neural network (CNN) training and testing. The experimental results demonstrated that the proposed method severally obtains the average MSE, PSNR, and SSIM values of 0.0055, 22.7950, and 0.8241, which outperformed some existing traditional and unsupervised learning-based methods. Moreover, our method can register 3D abdominal CT images with shortest time and is expected to become a real-time method for clinical application.

Liver segmentation from abdominal CT volumes based on level set and sparse shape composition.

BACKGROUND AND OBJECTIVE: Liver segmentation from abdominal CT volumes is a primary step for computer-aided surgery and liver disease diagnosis. However, accurate liver segmentation remains a challenging task for intensity inhomogeneity and serious pathologies occurring in liver CT volume. This paper presents a novel framework for accurate liver segmentation from CT images. METHODS: Firstly, a novel level set integrated with intensity bias and position constraint is applied, and for normal liver, the generated liver regions are regarded as the final results. Then, for pathological liver, a sparse shape composition (SSC)-based method is presented to refine liver shapes, followed by an improved graph cut to further optimize segmentation results. The level set-based method is capable of overcoming intensity inhomogeneity in object regions, and the SSC- and graph cut-based strategy has outstanding power to address under-segmentation appearing in pathological livers. RESULTS: The experiments conducted on public databases SLIVER07 and 3Dircadb show that the proposed method can segment both healthy and pathological liver effectively. The segmentation performance in terms of mean ASD, RMSD, MSD, VOE and RVD on SLIVER07 are 0.9mm, 1.8mm, 19.4mm, 5.1% and 0.1%, respectively, and on 3Dircadb are 1.6mm, 3.1mm, 27.2mm, 9.2% and 0.5%, respectively, which outperforms many existing methods. CONCLUSIONS: The proposed method does not require complex training procedure on numerous liver samples, and has satisfying and robust segmentation performance on both normal and pathological liver in various shapes.

Autophagy-Lysosome Pathway in Renal Tubular Epithelial Cells Is Disrupted by Advanced Glycation End Products in Diabetic Nephropathy.

It has been suggested that autophagy protects renal tubular epithelial cells (TECs) from injury in diabetic nephropathy (DN). However, the manner in which the autophagy-lysosome pathway is changed in this state remains unclear. In this study of DN, we investigated the autophagic activity and lysosomal alterations in vivo and in vitro. We found that autophagic vacuoles and SQSTM1-positive proteins accumulated in TECs from patients with DN and in human renal tubular epithelial cell line (HK-2 cells) treated with advanced glycation end products (AGEs), the important factors that involved in the pathogenesis of DN. In HK-2 cells, exposure to AGEs caused a significant increase in autophagosomes but a marked decrease in autolysosomes, and the lysosomal turnover of LC3-II was not observed, although LC3-II puncta were co-localized with the irregular lysosomal-associated membrane protein1 granules after AGEs treatment. Furthermore, lysosomal membrane permeabilization was triggered by AGEs, which likely resulted in a decrease in the enzymatic activities of cathepsin B and cathepsin L, the defective acidification of lysosomes, and suppression of the lysosomal degradation of DQ-ovalbumin. Oxidative stress evoked by AGEs-receptor for AGE interaction likely played an important role in the lysosomal dysfunction. Additionally, ubiquitinated proteins were co-localized with SQSTM1-positive puncta and accumulated in HK-2 cells after exposure to AGEs, indicating blocked degradation of SQSTM1-positive and ubiquitinated aggregates. Taken together, the results show that lysosomal membrane permeabilization and lysosomal dysfunction are triggered by AGEs, which induce autophagic inactivation in TECs from patients with DN. Disruption of the autophagy-lysosome pathway should be focused when studying the mechanisms underlying DN.

[Adsorption kinetics and mechanism of lead (II) on polyamine-functionalized mesoporous activated carbon].

Bagasse mesoporous carbon was prepared by microwave assisted H3 PO4 activation. Amido and imido groups were modified with ethanediamine on the channels' surface of mesoporous carbon through nitric oxidation and amide reaction. The influence of Pb(II) concentration, adsorption time on Pb(II) adsorption on the ethanediamine-modified mesoporous carbon (AC-EDA) was investigated. The adsorption kinetics and mechanism were also discussed. The results showed that AC-EDA had a great performance for Pb(II) adsorption, and more than 70% of Pb(II) was adsorbed in 5 minutes. The adsorption amount of Pb(II) on the carbon increased with the increase of solution pH in acidic conditions. It was found that AC-EDA had different binding energies on different adsorption sites for Pb(II) separation. The Pb(II) adsorption process on AC-EDA was controlled by intra-particle diffusion in the first 3 min, and then film diffusion played the important pole on the adsorption. The adsorption amount increased with the increase of temperature, indicating the adsorption was an endothermic reaction. The high adsorption energy (> 11 kJ x mol(-1)) implied that the) adsorption was a chemical adsorption. The XPS of AC-EDA before and after Pb(II) adsorption showed that the polyamine group was involved in the adsorption, and should be a main factor of the high efficient adsorption.

[Effect of different tidal volume ventilations on atelectasis in patients during general anesthesia by CT scan].

OBJECTIVE: To investigate the effect of different tidal volume ventilations on the amount of atelectasis during general anesthesia. METHODS: Twenty adults, ASA physical status I and status II patients, who were scheduled for elective excision of intracranial lesion were randomly divided into 2 groups: Group TV (traditional tidal volume ventilation, 10 mL/kg) and Group LV (low tidal volume ventilation, 6 mL/kg). Atelectasis, as determined by CT and artery blood gas (ABG) analysis, was measured before the anesthesia, after the tracheal intubation, and at the end of the operation, respectively. Respiratory mechanical parameters were measured at 30, 120, and 240 min after the intubation. RESULTS: After the tracheal intubation, CT scan showed obvious atelectasis in both groups. The atelectasis area was(4.35+/-2.15)cm2 (3.12%+/-1.94%) in the TV group and (4.80+/-2.45)cm2 (3.89%+/-2.11%) in the LV group, with a nonsignificant difference between the 2 groups. At the end of the operation, there was no significant increase in the amount of atelectasis between and within the 2 groups. Artery blood gas analysis showed no difference after the tracheal intubation and at the end of the operation in either group. Ppeak, Pplat, Pmean and lung compliance(Cst)were significantly higher in the TV group than those in the LV group. CONCLUSION: Low tidal volume(6 mL/kg) ventilation is more feasible during general anesthesia in patients with healthy lungs, and it does not increase the atelectasis and impairment of gas exchange.

[Chemoresistance of CD133(+) tumor stem cells from human brain glioma].

OBJECTIVE: To explore the multidrug resistance (MDR) mechanism of ABC superfamily transporters in the tumor stem cells(TSC) from human brain glioma tissues. METHODS: Samples of glioma were obtained from 30 patients undergoing microsurgical tumor resection. The CD133(+) cells and CD133(-) cells from these tumor specimens were isolated by magnetic activated cell sorting(MACS). These cells were cultured, proliferated and passaged. The protein and activity expression of multidrug-resistance protein 1(MDR1) and multidrug-resistance associated protein 1(MRP1) were analyzed between CD133(+) and CD133(-) cells by immunocytochemistry and RT-PCR respectively. RESULTS: CD133(+) cells generated free floating neurosphere like brain tumor spheres(BTS) and abnormal proliferating capacity in the serum-free medium(SFM) in vitro. Three cases from glioblastoma stem cells could form BTS in the complete medium, and could be cultured for 1-3 passages. The range of positive cell proportion for MDR1 and MRP1 expression in CD133(+) cells was 18%-67% and 23%-73% respectively. The expression levels of MDR1 and MRP1 mRNA were higher in CD133(+) glioma stem cells than those in the differentiated tumor cells(TC), the protein activity was increased to 16.1 and 19.6 times respectively compared with that of TC. The protein and activity expression were positively related to the pathological grades of tumors. MDR1 or MRP1 drug resistance was not expressed in all the tumors and there was obvious correlation between MDR1 and MRP1. CONCLUSION: Only a small proportion of cells in the heterogeneous glioma is CD133(+) brain tumor stem cells which display the strong capacity of self-renewing, abnormal proliferation and intrinsic multidrug resistance to traditional chemotherapy. The high expression of MDR1 and MRP1 by the CD133(+) brain tumor stem cells is one of the main mechanisms in the chemoresistance of tumors. CD133(+) brain tumor stem cells can be served as the root of multidrug resistance and key therapeutic target for glioma chemotherapy.

[Isolation and identification of brain tumor stem cells from human brain neuroepithelial tumors].

OBJECTIVE: To establish a simplified culture system for the isolation of brain tumor stem cells (BTSCs) from the tumors of human neuroepithelial tissue, to observe the growth and differentiation pattern of BTSCs, and to investigate their expression of the specific markers. METHODS: Twenty-six patients with brain neuroepithelial tumors underwent tumor resection. Two pieces of tumor tissues were taken from each tumor to be dissociated, triturated into single cells in sterile DMEM-F12 medium, and then filtered. The tumor cells were seeded at a concentration of 200,000 viable cells per mL into serum-free DMEM-F12 medium simply supplemented with B27, human basic fibroblast growth factor (20 microg/L), human epidermal growth factor (20 microg /L), insulin (4 U/L), L-glutamine, penicillin and streptomycin. After the primary brain tumor spheres (BTSs) were generated, they were triturated again and passed in fresh medium. Limiting dilution assay was performed to observe the monoclone formation. 5-bromodeoxyuridine (BrdU) incorporation test was performed to observe the proliferation of the BTS. The BTSCs were cultured in mitogen-free DMEM-F12 medium supplemented with 10% fetal bovine serum to observe their differentiation. Immunocytochemistry was used to examine the expression of CD133 and nestin, specific markers of BTSC, and the rate of CD133 positive cells. RESULTS: Only a minority of subsets of cells from the tumors of neuroepithelial tissue had the capacity to survive, proliferate, and generate free-floating neurosphere-like BTSs in the simplified serum-free medium. These cells attached to the poly-L-lysine coated coverslips in the serum-supplemented medium and differentiated. The BTSCs were CD133 and nestin positive. The rate of CD133 positive cells in the tumor specimens was (21 +/- 6.2)% - (38 +/- 7.0)%. CONCLUSION: A new simplified culture system for the isolation of BTSCs is established. The tumors of human neuroepithelial tissue contain CD133 and nestin positive tumor stem cells which can be isolated, proliferate and differentiate in vitro and give rise to brain tumor spheres. This tumorigenic subset may provide both a platform for brain tumor research and a target for clinical treatment.

Photo-degradation of acid-red 3B dye catalyzed by TiO2 nanotubes.

TiO2 nanotube precursor was synthesized by the hydrothermal reaction of TiO2 powders with NaOH solution and the properties of the nanotube materials were tuned using different post-treatments. Transmission electron microscopic (TEM) observation revealed that the nanotube could be obtained by either a direct rinse with acid solution or rinse with distilled water followed by acid solution. The results of X-ray diffraction (XRD) and inductively coupled plasma (ICP) analysis indicated that the nanotube material was composed of H2Ti2O5 x H2O. In addition, the photocatalytic activities of the resulting catalysts were found to be strongly dependent on the post-treatment. The results of the photocatalytic reaction showed that the degradation of Acid-red 3B dye fitted pseudo-zero-order kinetics and TiO2 nanotube prepared under direct rinse with acid solution exhibited a higher catalytic efficiency compared to other catalysts.

[In vitro gene transfection by magnetic iron oxide nanoparticles and magnetic field increases transfection efficiency].

OBJECTIVE: To evaluate the feasibility of using iron oxide nanoparticles as gene vector and the effect of magnetic field on efficiency of transfection. METHODS: Iron oxide nanoparticles were prepared by alkaline precipitation of divalent and trivalent iron chloride. The surface of iron oxide nanoparticles was modified by self-assembled poly-L-lysine to form particle complexes (IONP-PLL). Transfection was determined by delivering reporter gene, PGL2-control encoding luciferase, to different cell lines using IONP-PLL as vector. The effect of magnetic field on efficiency of transfection was determined using Nd-Fe-B permanent magnet. RESULTS: Foreign gene could be delivered to various cell lines by IONP-PLL and expressed with high efficiency, but the transfection efficiency and time course varied in the different cell lines studied. Magnetic field could enhance the efficiency of transfection by 5 - 10 fold. CONCLUSION: IONP-PLL can be used as a novel non-viral gene vector in vitro, which offers a basis for gene delivery in vivo.

[Pathogens and drug resistance of nosocomial pneumonia after intracranial surgery].

OBJECTIVE: To determine the antimicrobial resistance and bacterial distribution of nosocomial pneumonia in neurosurgical patients. METHODS: We analyzed and counted the result of sputum culture, drug sensibilities test, and the rate of nosocomial pneumonia after intracranial surgery of all the patients in the Department of in Neurosurgery our hospital in 2002. RESULTS: The rate of nosocomial pneumonia after intracranial surgery was 6.2%. The first 5 strains were pseudomonas aeruginosa, acinetobacter, enterobacteriaceae, klebsiella, and staphylococcus epidermidis. Statistics of drug sensibility test suggested:the rate of ampicillin and cefuroxime resistance was over 83%. Gram-negative bacterium was the first sensitive to sulperazon and imipenem. Gram-positive bacterium was the first sensitive to vancomycin, ampicillin/sulbactam and rifampicin. CONCLUSION: The rate of neurosurgical infection was high. The most common pathogens were gram-negative bacteria. Drug resistance was serious.