CRISPR-Cas12a based fluorescence assay for organophosphorus pesticides in agricultural products.

Herein, we propose a sensitive fluorescent assay for organophosphorus pesticides (OPs) detection based on a novel strategy of activating the CRISPR-Cas12a system. Specifically, acetylcholinesterase (AChE) hydrolyzes acetylthiocholine into thiocholine (TCh). Subsequently, TCh induces the degradation of MnO2 nanosheets and generates sufficient Mn2+ ions to activate the Mn2+-dependent DNAzyme. Then, as the catalytic product of activated DNAzyme, the short DNA strand activates the CRISPR-Cas12a system to cleave the fluorophore-quencher-labeled DNA reporter (FQ) probe effectively; thus, increasing the fluorescence intensity (FI) in the solution. However, in the presence of OPs, the activity of AChE is suppressed, resulting in a decrease in FI. Under optimized conditions, the limits of detection for paraoxon, dichlorvos, and demeton were 270, 406, and 218 pg/mL, respectively. Benefiting from the outstanding MnO2 nanosheets properties and three rounds of enzymatic signal amplification, the proposed fluorescence assay holds great potential for the detection of OPs in agricultural products.

Potential of PKM2 as a drug target in mouse models with type 1 diabetes mellitus.

BACKGROUND: This study aimed to determine the effect of PKM2 knockout in STZ induced type 1 diabetes mellitus (T1D) mouse models and to explore the possible mechanism. METHOD: PKM2fl/fl C57BL/6 mouse was backcrossed with Ins-1cre C57BL/6 mouse to generate ß-cell-specific PKM2 knockout mouse after tamoxifen administration. The expression level of PKM2 in pancreas tissues was detected by quantitative reverse-transcription polymerase chain reaction and western blot analysis. The blood glucose levels in STZ induced T1D mouse models were measured to validate the establishment of T1D models. The pathological changes of T1D mouse were examined by hematoxylin and eosin. The oxidative stress (OS) and inflammatory response in T1D mouse were determined by measuring the expression levels of malondialdehyde, superoxide dismutase, and 8-OHdG in pancreatic tissues and the serum levels of interleukin-6 and tumor necrosis factor-α. The ability to catabolize glucose was assessed through intraperitoneal glucose tolerance test and insulin tolerance test. RESULTS: ß-cell-specific PKM2 knockout was successfully achieved in PKM2fl/flcre+ mouse. T1D mouse with PKM2 knockdown had decreased blood glucose level and suppressed cell apoptosis. PKM2 knockout in T1D mouse attenuated ß cell injury. OS and inflammatory response in T1D mouse with PKM2 knockout were also suppressed compared with T1D mouse without PKM2 knockout. CONCLUSION: PKM2 knockout in T1D mouse can attenuate OS and inflammatory response as well as decrease blood glucose level, suggesting the potential of PKM2 as a drug target for T1D treatment.

Enantioselective determination of phenthoate enantiomers in plant-origin matrices using reversed-phase high-performance liquid chromatography-tandem mass spectrometry.

Phenthoate is a chiral organophosphate pesticide with a pair of enantiomers which differ in toxicity, behavior and insecticidal activity, and its acute toxicity on human health owing to the inhibition of acetylcholinesterase highlights the need for enantioselective detection of enantiomers. Therefore, this study aimed to establish a simple rapid method for separation and detection of phenthoate enantiomers in fruits, vegetables and grains. The enantiomers were separated using reversed-phase high-performance liquid chromatography-tandem mass spectrometry for the first time. Rapid chiral separation (within 9 min) of the target compound was achieved on a chiral OJ-RH column with the mobile phase of methanol-water = 85:15(v/v), at a flow rate of 1 ml/min and a column temperature of 30°C. Acetonitrile and graphitized carbon black were used as the extractant and sorbent for pretreatment, respectively. This method provides excellent linearity (correlation coefficient ≥0.9986), high sensitivity (limit of quantification 5 µg/kg and limit of detection <0.25 µg/kg), satisfactory mean recoveries (76.2-91.0%) and relative standard deviation (intra-day RSDs ranged from 2.0 to 7.9% and inter-day RSDs ranged from 2.4 to 8.4%). In addition, a field trial to explore the stereoselective degradation of phenthoate enantiomers in citrus showed that (-)-phenthoate degraded faster than its antipode, resulting in the relative accumulation of (+)-phenthoate.

Determination of five pesticides in kumquat: Dissipation behaviors, residues and their health risk assessment under field conditions.

The present study was carried out to profile the dissipation patterns and residues of five pesticides (triazophos, profenofos, chlorpyrifos, etoxazole and bifenthrin) on kumquat using QuEChERS method coupled with HPLC-MS/MS. The corresponding dietary health risks were also estimated. In the method validation, satisfactory results of good linearity (r2 ≥ 0.9956), sensitivity (limits of quantification ≤0.01 mg/kg), recoveries (71.0-95.7%) with relative standard deviations (0.70-9.4%) were obtained. The half-lives of the five pesticides in kumquat were 13.6-38.5 d under field conditions according to first-order kinetics. Based on the final residue experiment, dietary exposure risks of profenofos, chlorpyrifos, etoxazole and bifenthrin were all acceptably low, with RQc and RQa values of 0.00199-0.122 and 0.00145-0.200, respectively. However, exposure intake of triazophos posed unacceptable acute and chronic health risks for Chinese residents, especially for children with RQa and RQc up to 4.25 and 2.19. Forbidden use suggestion of triazophos and recommended MRLs of profenofos and bifenthrin were put forward in kumquat for safe production and consumption. This work was significant in providing guidance on appropriate application and MRL establishment of pesticides in kumquat.

[Expression and Clinical Significance of MiR-146a and MiR-221 in Childhood Acute T Lymphoblastic Leukemia].

OBJECTIVE: To investigate the expression of miR-146a and miR-211 in peripheral blood mononuclear cells (PBMNC) of children with acute T-lymphoblastic leukemia (T-ALL) and their clinical significance. METHODS: One hundred and thirty newly diagnosed children with T-ALL from Hainan Third People's Hospital (T-ALL group) and 50 healthy persons (control group) were selected. The newly diagnosed T-ALL patients before treatment were taken as initial group, the patients reachived complete remission after induction therapy for 33 days were taken as remission group (n=98), the patients not reachived complete remission after induction therapy fore 33 days were taken as rafractory group (n=32). The expression levels of miR-146a and miR-221 in PBMNC were detected by real-time fluorescence quantitative PCR. ROC curve analysis was used to evaluate the diagnostic value of miR-146a and miR-221 for T-ALL, Pearson correlation analysis was used to estimate the correlation of miR-146a and miR-221 expression with white blood cell count in children with T-ALL. RESULTS: The expression levels of miR-146a and miR-221 of PBMNC in T-ALL group were significantly higher than those in control group (5.83±1.54 vs 0.96±0.17) (7.13±2.60 vs 1.64±0.51) (P＜0.01). The expression levels of miR-146a and miR-221 in refractory group were significantly higher than those in remission group and initial group (8.74±2.35 vs 1.70±0.63 and 5.83±1.54) (11.316±4.83 vs 2.62±0.85 and 7.13±2.60) (P＜0.01). The expression levels of miR-146a and miR-221 correlated with white blood cell count, risk typing and MRD (P＜0.05). ROC curve analysis showed that the best cutoff values of miR-146a and miR-221 for diagnosing childhood T-ALL were 3.90 and 5.28, resoectively. While the AUC (95% CI) of the T-ALL jointy diagnosed by miR-146a and miR-221 was 0.835 (0.764-0.892), and it's sensitivity and specificity were 85.0% and 77.2%, respectively. The correlation analysis showed that the expression levels of miR-146a and miR-221 in PBMNC of children with T-ALL positively correlated with the white blood cell count (r=0.705, r=0.653, P＜0.01), and that of miR-146a positively correlated with miR-221 (r=0.784, P＜0.01). CONCLUSION: The expression of miR-146a and miR-221 is up-regulated in children with T-ALL and closely relates with the prognosis of children with T-ALL. The combined detection of miR-146a and miR-221 is certain value for diagnosis of T-ALL.

Simultaneous Enantioselective Determination of Two New Isopropanol-Triazole Fungicides in Plant-Origin Foods Using Multiwalled Carbon Nanotubes in Reversed-Dispersive Solid-Phase Extraction and Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.

A simple and sensitive enantiomeric analytical method was established for the determination of two new isopropanol-triazole fungicides mefentrifluconazole and ipfentrifluconazole in plant-origin foods using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The best enantioseparation of the four target stereoisomers was achieved on a Chiral MX(2)-RH column within 7 min by reversed-phase liquid chromatography, which is a significant improvement in the resolution of different chiral compounds under one set of conditions. A simple and effective pretreatment procedure was developed for the extraction and purification of the two target chiral fungicides using reversed-dispersive solid-phase extraction (r-DSPE) with multiwalled carbon nanotubes (MWCNTs). The influence of the type and amount of MWCNTs on the purification efficiencies and recoveries was evaluated. The mean recoveries for all four stereoisomers were in the range of 76.9-91.2%, with relative standard deviation (RSD) values below 7.2%. The limit of quantification (LOQ) of all stereoisomers of mefentrifluconazole and ipfentrifluconazole was 5 µg/kg for all tested matrixes. The results of the method validation and real samples analysis confirm that the established method is efficient and reliable for the enantiomeric determination of mefentrifluconazole and ipfentrifluconazole in plant-origin food samples.

Synthesis of micro-mesoporous ZSM-5 zeolite with microcrystalline cellulose as co-template and catalytic cracking of polyolefin plastics.

Micro-mesoporous ZSM-5 with different Si/Al ratios (MZ-X, X = 27, 80, 150) were synthesized by adding microcrystalline cellulose (MCC) as co-template into the hydrothermal synthesis process of zeolites. The resultant ZSM-5 were used for catalytic cracking of high density polyethylene (HPDE) and polypropylene. It was found that introduction of MCC significantly enhanced the formation of mesopores and strong acid sites. MZ-27 achieved the highest oil yield: 21.5% for HPDE and 32.1% for polypropylene, and the light aromatics (BTEX) selectivity therein were 87.6% and 79.7%, respectively. HZ-150 (MCC-free ZSM-5, Si/Al = 150) achieved the highest gas yield: 85.4% for HDPE and 76.7% for polypropylene, and the light olefins (C[double bond, length as m-dash] 2-4) selectivity therein were 44% and 48.3%, respectively. The dense acidic sites and mesoporous structure of MZ-27 were responsible for its better activity for producing aromatic products. The moderate acidity and microporous structure of HZ-150 were helpful for producing light olefins from catalytic cracking of polyolefin plastics.

The prognostic value of tumour-associated macrophages in Non-Hodgkin's lymphoma: A systematic review and meta-analysis.

Tumour-associated macrophages (TAMs) play an important role in the tumour environment and were reported to be associated with poor prognosis in several tumours. However, the prognostic significance of TAMs in Non-Hodgkin's Lymphoma (NHL) remains controversial. Consequently, we aimed to evaluate the relationship between subpopulations of TAMs and clinical outcomes in NHL patients. We did a comprehensive search of the PubMed, elsevier ScienceDirect, and Cochrane databases and extracted hazard ratio (HR) and their corresponding 95% confidence intervals (95% CIs) from eligible studies. Pooling total effect value by the stata statistical software and analysing correlation of TAMs with overall survival (OS) and progression-free survival (PFS). Furthermore, subgroup analysis and sensitivity analysis were also conducted. We deemed eleven studies, including 1211 NHL patients. Our study demonstrated that high-density CD68+ TAMs are associated with poor OS (HR: 1.17; 95% CI, 0.81-1.54; P = .000) and poor PFS (HR: 1.15; 95% CI, 0.63-1.67; P = .000) compared with low-density CD68+ TAMs in the tumour microenvironment. Similarly, high-density CD163+ TAMs can also predict poor OS (HR: 1.52; 95% CI, 1.11-1.92; P = .000) and shorter PFS (HR: 1.52; 95% CI, 0.73-2.30; P = .000). In addition, the high CD163+ /CD68+ TAMs ratio is significantly correlated with poor OS (HR: 3.59; 95% CI, 0.77-6.40; P = .013). However, in our subgroup analysis, high-density CD68+ TAMs in the tumour microenvironment is associated with better OS (HR: 0.75; 95% CI, 0.41-1.09; P = .000) in NHL patients treated with rituximab chemotherapy. Our results suggest that TAMs are a robust predictor of outcomes in NHL.

Artesunate prevents type 1 diabetes in NOD mice mainly by inducing protective IL-4-producing T cells and regulatory T cells.

Type 1 diabetes (T1D) is an autoimmune disease characterized by the immune-mediated destruction of insulin-producing ß cells. Recent studies showed that in addition to malaria, artemisinin and its derivative, artesunate (AS), could alleviate several autoimmune diseases. However, whether AS has a role in the prevention or treatment of T1D is still unknown. Therefore, in this study we administrated AS or DMSO in the drinking water of nonobese diabetic (NOD) mice, a mouse model of T1D. We found that AS administration significantly prevented the incidence of T1D. The frequency of IL-4-producing CD4+ single-positive T cells and CD8+ T cells was significantly elevated, and IFN-γ-producing T cells were reduced in the spleen and pancreatic lymph nodes. In the pancreas, the skewing to IL-4-producing T cells was also observed. In addition, more regulatory T cells were found in the pancreas. mRNA levels of proinflammatory cytokines, including TNF-α and IL-6, were decreased. In addition, AS administration promoted the functional maturity of ß cells in vitro. Our findings demonstrate that AS administration can prevent T1D in NOD mice mainly by reducing autoimmune T cells and increasing protective T cells. Our data constitute the first functional study of AS in T1D, which may provide a new rationale for future translational studies.-Li, Z., Shi, X., Liu, J., Shao, F., Huang, G., Zhou, Z., Zheng, P. Artesunate prevents type 1 diabetes in NOD mice mainly by inducing protective IL-4-producing T cells and regulatory T cells.

Synthesis of a magnetic polystyrene-based cation-exchange resin and its utilization for the efficient removal of cadmium (II).

A magnetic cation-exchange resin (MCER) was prepared by copolymerization of oleic acid-grafted magnetite with styrene, divinylbenzene (DVB), and triallylisocyanurate (TAIC) for removing Cd(II) from wastewater. A non-magnetic cation-exchange polystyrene resin (CEPR) was also prepared as a reference. Structural and morphological analyses revealed that the MCER and CEPR were mesoporous microspheres; the MCER contained about 25% Fe3O4. The influence of temperature, pH, contact time, and the initial concentration of Cd(II) on the adsorption of Cd(II) was investigated. The maximum adsorption capacity of the MCER reached 88.56 mg/g, which was achieved at 343 K using a Cd(II) initial concentration of 200 mg/L. The adsorption processes attained equilibrium within 120 min for the MCER and 300 min for the CEPR, and were well described by a pseudo-second-order kinetic model. Furthermore, the equilibrium adsorption data fitted the Freundlich isotherm model better than the Langmuir model. The superior magnetic response and regeneration of the MCER make it a good candidate as an adsorbent for removing Cd(II) from wastewater.

DcR3 induces proliferation, migration, invasion, and EMT in gastric cancer cells via the PI3K/AKT/GSK-3ß/ß-catenin signaling pathway.

BACKGROUND: Decoy receptor 3 (DcR3) has been reported to be overexpressed in a wide variety of malignancies and is correlated with tumorigenesis and progression. In gastric cancer (GC), DcR3 overexpression is associated with lymph node and distant metastasis, as well as poor prognosis. However, the functional role of DcR3 expression in GC remains elusive. PURPOSE: The aim of this study is to elucidate the direct role of DcR3 in regulating GC progression and metastasis and identify the potential mechanism. METHODS: DcR3 expression was stably knocked down in HGC27 and MKN28 cells by transfecting the cells with DcR3 shRNA using lentiviral vector system. After the knockdown of DcR3 was confirmed, cell proliferation, colony formation, cell cycle distribution, apoptosis, cell invasion and migration were assessed in vitro. In addition, Western blot analysis was performed to evaluate the expression of downstream mediators of DcR3. Comparisons between multiple groups were performed using one-way analysis of variance (ANOVA) or unpaired Student's t-test. Differences were considered significant at P<0.05. RESULTS: Our findings demonstrate that DcR3 induces proliferation, migration, invasion, and promotes epithelial-mesenchymal transition (EMT) of GC cells. In addition, DcR3 increases the expression levels of several components of the PI3K/AKT/GSK-3ß/ß-catenin signaling pathway, such as p-AKT, GSK-3ß, p-GSK-3ß and ß-catenin. Additionally, DcR3 also enhances the expression of N-cadherin and Vimentin and decreases the expression of E-cadherin. CONCLUSION: In summary, the findings of this study indicate that during GC progression, DcR3 plays a key role in cell proliferation and invasion via the PI3K/AKT/GSK-3ß/ß-catenin signaling pathway. Thus, targeting DcR3 might be a potential therapeutic approach for the treatment of GC.

The Cohort Study on Prediction of Incidence of All-Cause Mortality by Metabolic Syndrome.

AIM: The aim was to evaluate the impact of metabolic syndrome (MS), MS individual components and 32 kinds of MS specific component combinations on all-cause mortality risk in a fixed cohort of MJ check-up population. METHODS: We observed the events of death in a fixed cohort, where the population was composed of 45,542 individuals aged 35-74 who were examined at MJ Health check-up Center in 1997 as baseline examination, and were followed up to 2005. Median duration of follow-up was 7.44 years. MS was defined according to the National Cholesterol Educational Program (the revised NCEP-ATPIII for Asian in 2004), the prevalence of MS was standardized according to China's fifth census data. We constructed common Cox regression model, simultaneously adjusting the classic risk factors (such as age, sex, smoking, alcohol drinking, physical activity, family history, etc.) to examine the relationship between MS, MS individual components and 32 kinds of MS specific component combinations on the occurrence of death with the fixed cohort. RESULTS: The standardized prevalence of MS was 29.75% (male: 30.36%, female: 29.51%). There were 1,749 persons who died during the median 7.44-years follow-up, the mortality rate was 46 per 10,000 person years. The mortality rates were 71 and 35 per 10,000 person years for those with and without MS, respectively. After adjustment for age, sex and classical risk factors, compared with subjects without MS, the hazard ratio of all-cause mortality was 1.26 (95% CI: 1.14-1.40). The all-cause mortality were more highly significant than other combinations (P <0.05) when the following combinations exist: "elevated blood pressure", "elevated fasting plasma glucose + low high-density lipoprotein cholesterol", "elevated blood pressure + elevated triglyceride + elevated fasting plasma glucose", "elevated fasting plasma glucose + low high-density lipoprotein cholesterol + elevated blood pressure + elevated triglyceride". After adjusting age, sex and classical risk factors, the HRs for those with 0 to 5 components were 1, 1.22, 1.25, 1.33, 1.66, and 1.92, respectively. There was a significant dose-response relationship (P for liner trend <0.001) between the number of MS components and the risk of all-cause mortality in the overall fixed cohort sample. CONCLUSION: In a large scale middle-aged Taiwan check-up population, MS may be associated with a much higher risk for all-cause mortality. These results may underline the fact that MS is a non-homogeneous syndrome and have a significant impact on detecting high-risk individuals suffering from metabolic disorders for preventing and controlling death.

[Investigation of diagnostic method and treatment on acute appendicitis with acute intestinal obstruction as presenting manifestation].

OBJECTIVE: Prevention of the misdiagnosis of acute appendicitis when it first manifested as acute intestinal obstruction, and to search proper way of diagnosis and treatment for such event to provide the reference. METHODS: Clinical data of 33 acute appendicitis cases presented with acute intestinal obstruction in Beijing Tong Ren Hospital during January 2000 and December 2015 were analyzed retrospectively. RESULTS: All 33 patients were admitted to the Emergency Department with symptoms of various degrees abdominal pain and abdominal distension. There was no passage of gas and feces. The mean time of onset was (62.2±25.0) hours. The imaging examination showedthat all patients had complete bowel obstruction. Twenty one patients(63.6%) had peritonitis, three of whom developed with septic shock. Abdominal CT was performed in 17 patients preoperatively, which showed retention of gas and fluid in the small intestine in all the patients and 13 were suggestive of acute appendicitis. All of these patients received surgical treatment, 12 patients underwent laparoscopic exploration, and the remaining 21 patients received exploratory laparotomy during which acute appendicitis was confirmed to be the cause of intestinal obstruction, of whom 14(42.4%) was identified as mechanical intestinal obstruction. Nine patients underwent appendectomy and lysis of adhesion, five appendectomy and partial excision of the greateromentum. Nineteenpatients(57.6%) were identified as paralytic ileus and underwent appendectomy only. Twelve patients required respiratory and circulatory support and were admitted to ICU postoperatively. The mean duration time in ICU was(8.8±5.2) days. Postoperative pathology showedgangrene accompanied with perforation in the appendix. All patients were discharged without any complication. The length of hospital stay was (15.4±4.6) days. All patients were followed up for 3 ~ 12 months. One patient with chronic obstructive pulmonary disease developed repeated pulmonary infection and died of respiratory failure at 185 days postoperatively. The remaining patients were followed up and there were no patients developed intra-abdominalsepsis, intestinal obstruction, surgery-related complications, or death. CONCLUSION: Patients with acute appendicitis presenting with acute intestinal obstruction are mostly in severe condition. Clinical diagnosis for this patients is difficult and surgery should be performed as soon as possible.

In vitro apatite formation and drug loading/release of porous TiO2 microspheres prepared by sol-gel processing with different SiO2 nanoparticle contents.

Bioactive titania (TiO2) microparticles can be used as drug-releasing cement fillers for the chemotherapeutic treatment of metastatic bone tumors. Porous anatase-type TiO2 microspheres around 15 µm in diameter were obtained through a sol-gel process involving a water-in-oil emulsion with 30:70 SiO2/H2O weight ratio and subsequent NaOH solution treatment. The water phase consisted of methanol, titanium tetraisopropoxide, diethanolamine, SiO2 nanoparticles, and H2O, while the oil phase consisted of kerosene, Span 80, and Span 60. The resulting microspheres had a high specific surface area of 111.7 m(2)·g(-1). Apatite with a network-like surface structure formed on the surface of the microspheres within 8 days in simulated body fluid. The good apatite-forming ability of the microspheres is attributed to their porous structure and the negative zeta potential of TiO2. The release of rhodamine B, a model for a hydrophilic drug, was rapid for the first 6 h of soaking, but diffusion-controlled thereafter. The burst release in the first 6h is problematic for clinical applications; nonetheless, the present results highlight the potential of porous TiO2 microspheres as drug-releasing cement fillers able to form apatite.

[Role of the small intestinal decompression tube and Gastrografin in the treatment of early postoperative inflammatory small bowel obstruction].

OBJECTIVE: To evaluate the role of the small intestinal decompression tube (SIDT) and Gastrografin in the treatment of early postoperative inflammatory small bowel obstruction (EPISBO). METHODS: Twelve patients presented EPISBO after abdominal surgery in our department from April 2011 to July 2012. Initially, nasogastric tube decompression and other conventional conservative treatment were administrated. After 14 days, obstruction symptom improvement was not obvious, then the SIDT was used. At the same time, Gastrografin was injected into the small bowel through the SIDT in order to demonstrate the site of obstruction of small bowel and its efficacy. RESULTS: In 11 patients after this management, obstruction symptoms disappeared, bowel function recovered within 3 weeks, and oral feeding occurred gradually. Another patient did not pass flatus after 4 weeks and was reoperated. After postoperative follow-up of 6 months, no case relapsed with intestinal obstruction. CONCLUSION: For severe and long course of early postoperative inflammatory intestinal obstruction, intestinal decompression tube plus Gastrografin is safe and effective, and can avoid unnecessary reoperation.

MC3T3-E1 and RAW264.7 cell response to hydroxyapatite and alpha-type alumina adsorbed with bovine serum albumin.

Initial cell responses following implantation are important for inducing osteoconductivity. We investigated cell adhesion, spreading, and proliferation in response to native and bovine serum albumin (BSA)-adsorbed disc of hydroxyapatite (HA) or alpha-type alumina (α-Al2O3) using mouse MC3T3-E1 osteoblastic cells and mouse RAW264.7 macrophages. The adsorbed BSA inhibited adhesion and spreading of MC3T3-E1 cells, but did not affect MC3T3-E1 cell proliferation on HA and α-Al2O3 substrates. Thus, MC3T3-E1 cells quickly adhere to original HA before cell binding is impeded by adsorption of BSA in quantities sufficient to inhibit the adhesion of MC3T3-E1 cells. The adsorbed BSA inhibits adhesion of RAW264.7 cells to α-Al2O3, but not to HA. BSA adsorption does not affect RAW264.7 cell spreading and proliferation on both HA and α-Al2O3 substrates. Thus, BSA adsorbed on HA stimulates a different cell response than α-Al2O3. Moreover, quick adherence of osteoblast cells and monocyte-macrophage lineage cells plays a role in HA osteoconductivity.

Sol-gel synthesis, characterization, and in vitro compatibility of iron nanoparticle-encapsulating silica microspheres for hyperthermia in cancer therapy.

We prepared iron nanoparticle-encapsulating silica (FeSi) microspheres and tested their suitability as thermal seeds for hyperthermia in cancer therapy. These microspheres were prepared by introducing a ferric ion (Fe(3+)) into microspheres of a SiO(2) gel matrix derived from the hydrolysis of tetramethoxysilane in a water-in-oil emulsion that was then heat-treated at 850 °C in an argon atmosphere. The particles obtained were 5-30 µm in size and had a saturation magnetization up to 21 emu g(-1) and a coercive force of 86-133 Oe. Heat generation in an alternating current magnetic field of 300 Oe at 100 kHz was estimated to be 7.7-28.9 W g(-1). The in vitro cell biocompatibility of the microspheres was assessed by culturing rat fibroblast Rat-1 cells in medium supplemented with microspheres containing 6.7 % of iron nanoparticles. At microsphere concentrations of <7.5 g L(-1) proliferation of Rat-1 cells was not significantly inhibited.

In vitro assessment of poly(methylmethacrylate)-based bone cement containing magnetite nanoparticles for hyperthermia treatment of bone tumor.

Poly(methylmethacrylate) (PMMA)-based cements containing magnetite (C-PMMA/Fe(3)O(4)) is useful in hyperthermia treatment for bone tumor. We have prepared C-PMMA/Fe(3)O(4) by incorporating Fe(3) O(4) powders of different diameters (means of 300, 35, and 11 nm) into the polymerization reaction of methyl methacrylate monomer to develop a new bone cement with high heating efficiencies in alternating current (AC) magnetic fields. Further, we have investigated the in vitro heating capability of the cements in different AC magnetic fields. The mechanical strength and biocompatibility of the resultant cements were also assessed. Their heat generation strongly depends on the magnetite nanoparticle sizes and applied magnetic fields. The cement containing Fe(3)O(4) with mean diameter around 35 nm exhibited the highest heating capability in AC magnetic fields of 120 and 300 Oe at 100 kHz while that with mean diameter around 11 nm exhibited optimum heating capability in AC magnetic fields of 40 Oe at 600 kHz. The incorporation of Fe(3)O(4) into cement-30 wt % of the total amount of cement-did not significantly change the compressive strength of cement, and the proliferation of rat fibroblast Rat-1 cells on cement discs was not inhibited. Our investigations are useful for designing new PMMA/Fe(3)O(4) bone cement with high heating efficiencies and biocompatibilities for bone tumor treatments.

[Protection of the proximal colon segment during laparoscopic proctosigmoidectomy].

To evaluate the protection of proximal colon segment by analyzing blood supply disorder of proximal colon segment during laparoscopic proctosigmoidectomy(11 cases) in the Chaoyang Hospital of Capital Medical University. It is concluded that the disorder of blood supply of proximal colon segment during laparoscopic proctosigmoid surgery has two reasons. One is the anatomic factor of mesenteric vessels; the other is the inappropriate operative procedure. It is recommended that left colonic artery should be retained, and inferior mesenteric artery should be handled at a low level, thus, the risk of proximal intestine blood supply disorder caused by vascular anatomy variation can be reduced.

Current progress in inorganic artificial biomaterials.

In this review, recent advances in bioceramics, metallic biomaterials, and their composites are discussed in terms of their material properties and new medical applications. Porous calcium phosphate ceramics have attracted a lot attention as scaffolds for tissue-engineering purposes since the porous structure allows bone ingrowth. The addition of biodegradable polymers like chitosan, gelatin, and collagen have modified the degradability of the ceramics and their mechanical properties. Titanium (Ti) alloys are being developed for the fabrication of medical devices for the replacement of hard tissue such as artificial hip joints, bone plates, and dental implants because they are very reliable from the viewpoint of mechanical performance. Physical treatment such as grooving or setting a spatial gap on the surface of materials is applicable to improve the apatite formation on the Ti alloys. Blood-compatible polymers such as poly(ethylene glycol) have been successfully fixed on the surface of Ti via chemical bonding by an electrodeposition method. New functions have been explored in Ni-free, Co-Cr-Mo alloys and Mg alloys. In addition, yttrium-containing or phosphorus-containing glass microspheres (20-30 µm in diameter) and ferrimagnetic ceramic particles have exhibited great potential to realize minimally invasive treatment of cancer without surgical operation via in situ radiotherapy or hyperthermia of cancer, but it is still a major challenge to clarify the biological reaction between the artificial implants and living body before their application.