PU.1 Is Identified as a Novel Metastasis Suppressor in Hepatocellular Carcinoma Regulating the miR-615-5p/IGF2 Axis

Invasion and metastasis is the major cause of tumor recurrence, difficulty for cure and low survival rate. Excavating key transcription factors, which can regulate tumor invasion and metastasis, are crucial to the development of therapeutic strategies for cancers. PU.1 is a master hematopoietic transcription factor and a vital regulator in life. Here, we report that, compared to adjacent non-cancerous tissues, expression of PU.1 mRNA in metastatic hepatocellular carcinoma (HCC), but not primary HCC, was significantly down-regulated. In addition, levels of PU.1 mRNA in metastatic hepatoma cell lines MHCC97L and MHCC97H were much lower than in non-metastatic Hep3B cells. Transwell invasion assays after PU.1 siRNA transfection showed that the invasion of hepatoma cell lines was increased markedly by PU.1 knockdown. Oppositely, overexpression of PU.1 suppressed the invasion of these cells. However, knockdown and overexpression of PU.1 did not influence proliferation. Finally, we tried to explore the potential mechanism of PU.1 suppressing hepatoma cell invasion. ChIP-qPCR analysis showed that PU.1 exhibited a high binding capacity with miR-615-5p promoter sequence. Overexpression of PU.1 caused a dramatic increase of pri-, pre- and mature miR-615-5p, as well as a marked decrease of miR-615-5p target gene IGF2. These data indicate that PU.1 inhibits invasion of human HCC through promoting miR-615-5p and suppressing IGF2. These findings improve our understanding of PU.1 regulatory roles and provided a potential target for metastatic HCC diagnosis and therapy.

Abdominal wall mixed malignant germ cell tumor: a case report and review of literature

Abdominal wall mass is not uncommon in clinic, but it is very rare that germ cell tumors (GCTs) arise in the abdominal wall. The authors review the case of a 34-year-old female with abdominal wall mixed malignant GCT composed of embryonal carcinoma and teratoma and combine the relative literature to explain why GCTs originate from anterior abdominal wall.

Diagnostic values of microRNA-31 in peripheral blood mononuclear cells for pediatric pulmonary tuberculosis in Chinese patients

We investigated the diagnostic values of microRNA-31 in peripheral blood mononuclear cells (PBMCs) for pediatric pulmonary tuberculosis in Chinese patients. Sixty-five children with TB were selected for this study, which was conducted at the Department of Infectious Diseases People's Hospital of Laiwu City between December 2013 and December 2014. Sixty healthy children, selected in parallel, served as the control group. Real-time PCR was used to detect miR-31 expression in PBMCs. Serum levels of IL-6, TNF-α, NF-κB, and IFN-γ was detected by ELISA. ROC curve was employed to evaluate the diagnostic value of miR-31 in pediatric TB. Results show that expression of miRNA-31 in pediatric TB patients was significantly lower than that in normal children (0.48 ± 0.15 vs 1.23 ± 0.36, P < 0.05). By contrast, serum levels of the innate immune response cytokines, IL-6, TNF-α, NF-κB, and IFN-γ, were significantly higher in pediatric TB patients compared with normal children (P < 0.05). Furthermore, miRNA-31 expression was negatively correlated with serum levels of IL-6 (t = 69.91, P < 0.001), TNF-α (t = 10.96, P < 0.001), NF-κB (t = 39.94, P < 0.001), and IFN -γ (t = 37.94, P < 0.001). The cut-off threshold of miR-31 for pediatric TB diagnosis is 0.835 with a sensitivity of 98.5% and a specificity of 86.7%. Therefore, miR-31 has the potential to be a diagnostic marker in pediatric TB patients.

Root-soil air gap and resistance to water flow at the soil-root interface of Robinia pseudoacacia

During periods of water deficit, growing roots may shrink, retaining only partial contact with the soil. In this study, known mathematical models were used to calculate the root-soil air gap and water flow resistance at the soil-root interface, respectively, of Robinia pseudoacacia L. under different water conditions. Using a digital camera, the root-soil air gap of R. pseudoacacia was investigated in a root growth chamber; this root-soil air gap and the model-inferred water flow resistance at the soil-root interface were compared with predictions based on a separate outdoor experiment. The results indicated progressively greater root shrinkage and loss of root-soil contact with decreasing soil water potential. The average widths of the root-soil air gap for R. pseudoacacia in open fields and in the root growth chamber were 0.24 and 0.39 mm, respectively. The resistance to water flow at the soil-root interface in both environments increased with decreasing soil water potential. Stepwise regression analysis demonstrated that soil water potential and soil temperature were the best predictors of variation in the root-soil air gap. A combination of soil water potential, soil temperature, root-air water potential difference and soil-root water potential difference best predicted the resistance to water flow at the soil-root interface.

Long-term combined chemical and manure fertilizations increase soil organic carbon and total nitrogen in aggregate fractions at three typical cropland soils in China

Soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN) are important factors of soil fertility. However, effects of the combined chemical fertilizer and organic manure or straw on these factors and their relationships are less addressed under long-term fertilizations. This study addressed changes in SOC, TN, MBC and MBN at 0-20 cm soil depth under three 17 years (September 1990-September 2007) long-term fertilization croplands along a heat and water gradient in China. Four soil physical fractions (coarse free and fine free particulate organic C, cfPOC and ffPOC; intra-microaggregate POC, iPOC; and mineral associated organic C, MOC) were examined under five fertilizations: unfertilized control, chemical nitrogen (N), phosphorus (P) and potassium (K) (NPK), NPK plus straw (NPKS, hereafter straw return), and NPK plus manure (NPKM and 1.5NPKM, hereafter manure). Compared with Control, manure significantly increased all tested parameters. SOC and TN in fractions distributed as MOC > iPOC > cfPOC > ffPOC with the highest increase in cfPOC (329.3%) and cfPTN (431.1%), and the lowest in MOC (40.8%) and MTN (45.4%) under manure. SOC significantly positively correlated with MBC, cfPOC, ffPOC, iPOC and MOC (R(2) = 0.51-0.84, P < 0.01), while TN with cfPTN, ffPTN, iPTN and MTN (R(2) = 0.45-0.79, P < 0.01), but not with MBN, respectively. Principal component analyses explained 86.9-91.2% variance of SOC, TN, MBC, MBN, SOC and TN in each fraction. Our results demonstrated that cfPOC was a sensitive SOC indicator and manure addition was the best fertilization for improving soil fertility while straw return should take into account climate factors in Chinese croplands.

The extraction of different proteins in selenium enriched peanuts and their antioxidant properties

In this study, the selenium enriched peanuts and the different solubility proteins extracted from them were investigated. The dried defatted selenium enriched peanuts (SeP) powder (0.3147 μg/g) had a 2.5-fold higher mean total selenium concentration than general peanuts (GP) power (0.1233 μg/g). The SeP had higher concentration of selenium, manganese and zinc than that of GP, but less calcium. The rate of extraction of protein was 23.39% for peanuts and alkali soluble protein was the main component of protein in SeP, which accounted for 92.82% of total soluble protein and combined selenium was 77.33% of total selenium protein. In different forms of proteins from SeP, the WSePr due to higher concentration of selenium had higher DPPH free-radical scavenging activity, higher reducing activity and longer induction time than other proteins.

Changes in circulating endothelial progenitor cells predict responses of multiple myeloma patients to treatment with bortezomib and dexamethasone

Four cycles of chemotherapy are required to assess responses of multiple myeloma (MM) patients. We investigated whether circulating endothelial progenitor cells (cEPCs) could be a biomarker for predicting patient response in the first cycle of chemotherapy with bortezomib and dexamethasone, so patients might avoid ineffective and costly treatments and reduce exposure to unwanted side effects. We measured cEPCs and stromal cell-derived factor-1α (SDF-1α) in 46 MM patients in the first cycle of treatment with bortezomib and dexamethasone, and investigated clinical relevance based on patient response after four 21-day cycles. The mononuclear cell fraction was analyzed for cEPC by FACS analysis, and SDF-1α was analyzed by ELISA. The study population was divided into 3 groups according to the response to chemotherapy: good responders (n=16), common responders (n=12), and non-responders (n=18). There were no significant differences among these groups at baseline day 1 (P>0.05). cEPC levels decreased slightly at day 21 (8.2±3.3 cEPCs/μL) vs day 1 (8.4±2.9 cEPCs/μL) in good responders (P>0.05). In contrast, cEPC levels increased significantly in the other two groups (P<0.05). SDF-1α changes were closely related to changes in cEPCs. These findings indicate that change in cEPCs at day 21 in the first cycle might be considered a noninvasive biomarker for predicting a later response, and extent of change could help decide whether to continue this costly chemotherapy. cEPCs and the SDF-1α/CXCR4 axis are potential therapeutic targets for improved response and outcomes in MM patients.

Bioactivity of Essential Oil of Zingiber purpureum Rhizomes and Its Main Compounds against Two Stored Product Insects

The insecticidal and repellent activities of the essential oil extracted from Zingiber purpureum Roscoe rhizomes were evaluated against Tribolium castaneum (Herbst) and Lasioderma serricorne (L.) adults. During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Z. purpureum rhizomes was found to possess strong contact toxicity against T. castaneum and L. serricorne adults, with LD50 values of 39.0 and 16.3 µg per adult, respectively, and also showed strong fumigant toxicity against the two grain storage insects with LC50 values of 13.6 and 9.3 mg/liter of air, respectively. The essential oil obtained by hydrodistillation was investigated by gas chromatography-mass spectrometry. The main components of the essential oil were identified to be sabinene (48.1%), terpinen-4-ol (25.1%), and γ-terpinene (6.7%), followed by α-terpinene (4.3%), β-thujene (3.4%), and α-phellandrene (2.7%). Sabinene, terpinen-4-ol, and γ-terpinene were separated and purified by silica gel column chromatography and preparative thin-layer chromatography. Terpinen-4-ol showed the strongest contact toxicity against T. castaneum and L. serricorne (LD50=19.7 and 5.4 µg per adult, respectively) and also the strongest fumigant toxicity against T. castaneum and L. serricorne (LC50=3.7 and 1.3 mg/liter of air, respectively). Otherwise, sabinene and terpinen-4-ol were strongly repellent against T. castaneum as well as the essential oil, while γ-terpinene exhibited weaker repellency against T. castaneum compared with the positive control, DEET (N, N-diethyl-3-methylbenzamide). Moreover, only the essential oil exhibited strong repellency against L. serricorne, the three compounds exhibited weaker repellency against L. serricorne relative to DEET.

Twist1 is a potential prognostic marker for colorectal cancer and associated with chemoresistance

Twist1 is a highly conserved basic helix-loophelix transcription factor, and has been shown to play an important role in carcinogenesis of many tumors including colorectal cancer (CRC). Here we aimed to investigate the role of Twist1 in the clinical significance and chemoresistance in CRC. In this study, we examined the correlation between Twist1 expression and clinicopathological characteristics using immunohistochemistry in patients with CRC. The molecular mechanisms of Twist1 expression and its effects on chemosensitivity to 5-Fluorouracil and oxaliplatin were also explored by MTT assay, colony forming assay, flow cytometry assay. The results indicate that Twist1 is overexpressed in cancer tissue, and its positive expression are related to histological grade (P=0.004), T-stage (P=0.033), N-stage (P=0.000), M-stage (P=0.040), TNM stage (P=0.002) and recurrence (P=0.023). Moreover, positive Twist1 expression is correlated with poor overall survival in CRC patients (P<0.0001), and is a significant independent prognostic indicator. In addition, we show that knockdown of Twist1 inhibits proliferation, and increased the percentage of apoptotic cells of CRC cell lines. Our findings suggest that Twist1 promotes proliferation and chemoresistance of CRC cells. Twist1 may be a potential prognostic marker and a molecular target for therapies.

Testes-specific protease 50 promotes cell invasion and metastasis by increasing NF-kappaB-dependent matrix metalloproteinase-9 expression

The high mortality in breast cancer is often associated with metastatic progression in patients. Previously we have demonstrated that testes-specific protease 50 (TSP50), an oncogene overexpressed in breast cancer samples, could promote cell proliferation and tumorigenesis. However, whether TSP50 also has a key role in cell invasion and cancer metastasis, and the mechanism underlying the process are still unclear. Here we found that TSP50 overexpression greatly promoted cell migration, invasion, adhesion and formation of the stellate structures in 3D culture system in vitro as well as lung metastasis in vivo. Conversely, TSP50 knockdown caused the opposite changes. Mechanistic studies revealed that NF-κB signaling pathway was required for TSP50-induced cell migration and metastasis, and further results indicated that TSP50 overexpression enhanced expression and secretion of MMP9, a target gene of NF-κB signaling. In addition, knockdown of MMP9 resulted in inhibition of cell migration and invasion in vitro and lung metastasis in vivo. Most importantly, immunohistochemical staining of human breast cancer samples strongly showed that the coexpression of TSP50 and p65 as well as TSP50 and MMP9 were correlated with increased metastasis and poor survival. Furthermore, we found that some breast cancer diagnosis-associated features such as tumor size, tumor grade, estrogen receptors (ER) and progesterone receptors (PR) levels, were correlated well with TSP50/p65 and TSP50/MMP9 expression status. Taken together, this work identified the TSP50 activation of MMP9 as a novel signaling mechanism underlying human breast cancer invasion and metastasis.

pH-responsive iron manganese silicate nanoparticles as T1-T2* dual-modal imaging probes for tumor diagnosis

Magnetic resonance imaging (MRI) probes can be concentrated in tumors through grafting targeting agents. However, the clinical application of such targeted MRI probes is largely limited because specific agents are only used to target specific characteristics of cancer cells. The development of the MRI probes that can be used regardless of tumor types or their developmental stages is highly appreciated. The acidic tumor microenvironments and acidic organelles (endosomes/lysosomes) in cancer cells are universal phenomena of solid tumors, and nanoparticles can also accumulate in tumor tissues by enhanced permeability and retention (EPR) effect. Here, we reported the synthesis of pH-responsive T1-T2* dual-modal contrast agents based on iron manganese silicate (FeMn(SiO4)) hollow nanospheres, which can release Mn(2+) ions in acidic environments, exhibiting excellent ability as agents for magnetic resonance and red fluorescence imaging. MRI for mouse models revealed that the nanoprobes could accumulate in tumors via EPR effect and then distinguish tumors from normal tissues with the synergistic effect of T1 and T2* signal only 10 min after intravenous injection. Fluorescence imaging demonstrated that the nanoprobes could be endocytosed into cancer cells and located at their lower pH compartments. Moreover, the hollow nanospheres showed no obvious toxicity and inflammation to the major organs of mice, which made them attractive diagnostic agents for different types of cancers.

Surgical approach does not influence the outcome of incidental gallbladder carcinoma

Several reports claim that there is a risk that laparoscopic cholecystectomy (LC) might worsen the prognosis of unsuspected gallbladder cancer. The aim of this study was to evaluate whether the surgical approach influence the outcome in patients with incidental gallbladder carcinoma.

METHODS

A retrospective study was done of 28 patients who were diagnosed with unsuspected gallbladder carcinoma who had undergone cholecystectomy for benign gallbladder disease at our institution between 1999 and 2007. 20 patients (4 men and 16 women, aged from 37 to 81 years) undergoing LC (group A) and 8 patients (6 men and 2 women, aged from 43 to 88 years) undergoing open cholecystectomy (OC) (group B) with incidental diagnosed GC. We evaluated the outcome in the two groups correlating the cumulative survival rates with tumor stage and surgical technique (LC or OC), time of diagnosis (after or during cholecystectomy).

RESULTS

nine patients (69.2 %) in group A and four patients (30.8%) in group B had recurrence. Survival rate was statistically correlated to tumor stage (P<0.0001) Survival rate was statistically correlated with tumor stage but neither with the surgical approach used to perform cholecystectomy, nor with time of diagnosis (intra- or post-operatively).

CONCLUSION

These results would seem to lend support to the opinion that LC does not worsen the prognosis for incidental GC, regardless of whether the tumor was detected during or after cholecystectomy.

Simultaneous construction of PCR-DGGE-based predictive models of Listeria monocytogenes and Vibrio parahaemolyticus on cooked shrimps

The aim of this study was to simultaneously construct PCR-DGGE-based predictive models of Listeria monocytogenes and Vibrio parahaemolyticus on cooked shrimps at 4 and 10°C. Calibration curves were established to correlate peak density of DGGE bands with microbial counts. Microbial counts derived from PCR-DGGE and plate methods were fitted by Baranyi model to obtain molecular and traditional predictive models. For L. monocytogenes, growing at 4 and 10°C, molecular predictive models were constructed. It showed good evaluations of correlation coefficients (R(2) > 0.92), bias factors (Bf ) and accuracy factors (Af ) (1.0 ≤ Bf ≤ Af ≤ 1.1). Moreover, no significant difference was found between molecular and traditional predictive models when analysed on lag phase (λ), maximum growth rate (μmax ) and growth data (P > 0.05). But for V. parahaemolyticus, inactivated at 4 and 10°C, molecular models show significant difference when compared with traditional models. Taken together, these results suggest that PCR-DGGE based on DNA can be used to construct growth models, but it is inappropriate for inactivation models yet. This is the first report of developing PCR-DGGE to simultaneously construct multiple molecular models.

SIGNIFICANCE AND IMPACT OF THE STUDY

It has been known for a long time that microbial predictive models based on traditional plate methods are time-consuming and labour-intensive. Denaturing gradient gel electrophoresis (DGGE) has been widely used as a semiquantitative method to describe complex microbial community. In our study, we developed DGGE to quantify bacterial counts and simultaneously established two molecular predictive models to describe the growth and survival of two bacteria (Listeria monocytogenes and Vibrio parahaemolyticus) at 4 and 10°C. We demonstrated that PCR-DGGE could be used to construct growth models. This work provides a new approach to construct molecular predictive models and thereby facilitates predictive microbiology and QMRA (Quantitative Microbial Risk Assessment).

Increased of serum high-mobility group box chromosomal protein 1 correlated with intestinal mucosal barrier injury in patients with severe acute pancreatitis

Background

Secondary infections are the leading cause of death in patients with severe acute pancreatitis (SAP). The gut represents the main source of pancreatic contamination and related septic complications. High-mobility group box chromosomal protein 1 (HMGB1) was recently identified to play an important role in the SAP intestinal mucosal barrier dysfunction.

Objective

To investigate the correlation of high-mobility group box 1 (HMGB1) with intestinal barrier injury and infections in patients with severe acute pancreatitis (SAP).

Methods

The serum levels of HMGB1, amylase, lipase, and biochemical indicators were measured in 80 patients with SAP at the time of admission. Furthermore, relationship between their serum HMGB1 levels and intestinal barrier injury, infection and other clinical factors were analyzed.

Results

The mean value of serum HMGB1 levels was significantly higher in patients with SAP (6.02 ± 2.42 ng/mL) than that in healthy volunteers (1.87 ± 0.63 ng/mL). Serum HMGB1 levels were significantly positively correlated with the Ranson score. The HMGB1 levels were higher in patients with infection during the clinical course, the HMGB1 levels in non-survivors were higher than those in survivors, and positively correlated with DAO activity, L/M ratio, the concentration of endotoxin (R = 0.484, P <0.01).

Conclusions

HMGBl level of patients with severe acute pancreatitis was significantly increased, and can be used as an important indicator to determine the intestinal barrier dysfunction and infection.

[Effects of artificial disc replacement with angles on stress of adjacent intervertebral disc]

OBJECTIVE

To evaluate stress changes of intervertebral space and adjacent intervertebral space after artificial disc replacement with angles.

METHODS

Artificial disc replacement with angles were designed according to existing data. Axial pressure, flexion/extension, lateral bending and torsion loading were applied on finite element models of normal cervical discs on C4,5 segments, C4,5 segments with 0 degrees artificial cervical discs and C4,5 segments with 10 degrees artificial cervical discs, then stress changes of C4,5 space was observed. The same loadings were applied on finite element models of normal cervical discs on C4-C6 segments, C4,5 segments with 0 degrees, C4,5 segments with 10 degrees, then stress changes of replaced segments space and adjacent segment space were observed.

RESULTS

For C4,5 segments, 80 MPa/0 degrees artificial discs and 80 MPa/10 degrees artificial discs had the similar equivalent shear stress (Se), and were both larger than that of normal discs, when lateral bending were performed, 80 MPa/0 degrees artificial discs were closed to normal discs when axial pressure and flexion/extension were carried out, while 80 MPa/10 degrees artificial discs had a larger Se than that of normal ones,when torsion loading were applied, Szx/Szy stress of 80 MPa/0 degrees and 80 MPa/10 degrees artificial discs were closed to normal ones. For C4-C6 segments, the axial pressure, flexion/extension and lateral bending of C5,6 were all lower than normal discs after C4,5 discs were replaced by 80 MPa/10 degrees artificial discs, while Szx/Szy of torsion loading were closed to normal ones.

CONCLUSION

Artificial discs with 10 degrees have less influences on stress of adjacent intervertebral space and closer to mechanical property after being implanted into intervertebral space.

Reflective properties of randomly rough surfaces under large incidence angles

The reflective properties of randomly rough surfaces at large incidence angles have been reported due to their potential applications in some of the radiative heat transfer research areas. The main purpose of this work is to investigate the formation mechanism of the specular reflection peak of rough surfaces at large incidence angles. The bidirectional reflectance distribution function (BRDF) of rough aluminum surfaces with different roughnesses at different incident angles is measured by a three-axis automated scatterometer. This study used a validated and accurate computational model, the rigorous coupled-wave analysis (RCWA) method, to compare and analyze the measurement BRDF results. It is found that the RCWA results show the same trend of specular peak as the measurement. This paper mainly focuses on the relative roughness at the range of 0.16<σ/λ<5.35. As the relative roughness decreases, the specular peak enhancement dramatically increases and the scattering region significantly reduces, especially under large incidence angles. The RCWA and the Rayleigh criterion results have been compared, showing that the relative error of the total integrated scatter increases as the roughness of the surface increases at large incidence angles. In addition, the zero-order diffractive power calculated by RCWA and the reflectance calculated by Fresnel equations are compared. The comparison shows that the relative error declines sharply when the incident angle is large and the roughness is small.

Reevaluating significance of perineural invasion in gastric cancer based on double immunohistochemical staining

CONTEXT

In gastric cancer, the significance of perineural invasion remains controversial. Detecting perineural invasion with hematoxylin-eosin staining often leads to misdiagnosis. Labeling nerves by immunohistochemistry greatly assists perineural invasion detection, but it might also be misdiagnosed, because scattered cancer cells are difficult to recognize.

OBJECTIVE

To reevaluate the significance of perineural invasion in gastric cancer by double immunohistochemical staining that labels both nerves and cancer cells, and to examine agreements on perineural invasion detection between double immunohistochemical staining and single immunochemical staining (to label nerves) or hematoxylin-eosin staining.

DESIGN

We evaluated perineural invasion in 160 cases of gastric cancer with double immunohistochemical staining, single immunochemical staining, and hematoxylin-eosin staining, respectively; then we investigated the prognostic significance of perineural invasion.

RESULTS

Perineural invasion was detected in 65.0% (104 of 160), 38.1% (61 of 160), and 56.9% (91 of 160) of cases with double immunohistochemical staining, hematoxylin-eosin staining, and single immunohistochemical staining, respectively. Agreement was low between double staining and hematoxylin-eosin staining (κ = .34), and most false reports occurred in diffuse gastric cancer. Agreement between single immunochemical staining and double staining was good (κ = .67), but it declined in diffuse gastric cancer (κ = .28). Perineural invasion was closely associated with other clinicopathologic variables. Although perineural invasion-positive patients had a worse outcome than perineural invasion-negative patients, it was not an independent prognostic factor (P = .11; hazard ratio, 0.637; 95% confidence interval, 0.366-1.110).

CONCLUSIONS

Double immunohistochemical staining could improve accuracy of perineural invasion detection in gastric cancer, particularly in the diffuse type. Moreover, perineural invasion predicts a poor outcome in gastric cancer, but it cannot provide more information than traditional clinicopathologic variables.

Proteomic analysis identifies proteins associated with curcumin-enhancing efficacy of irinotecan-induced apoptosis of colorectal cancer LOVO cell

OBJECTIVE

We wish to implement a proteomics-based approach to pick and identify the proteins associated with curcumin enhancing efficacy of irinotecan inducing apoptosis of colorectal cancer LOVO cells, and further explore their synergy mechanism by bioinformatics.

METHODS

A colorectal cancer cell line (LOVO cell) treated by curcumin combined with irinotecan in different ways respectively was used as our comparative model. Protein spots were analyzed through MALDI-TOF/TOF. The location and function of differential protein spots were analyzed through UniProt database. Protein-protein interactions were examined through String software.

RESULTS

A total of 54 protein spots differentially expressed with 1.5-fold difference were picked, 11 of which were repeated. They mainly were involved in intracellular calcium pathways, cellular respiratory chain pathway and intracellular redox reaction pathways of LOVO cell. According to the function of various protein points, combining with varying curves of protein points in each treatment groups, we selected five interesting protein spots, 4 of which exists Protein-protein interactions, and they were close to the formation and reduction of disulfides in intracellular endoplasmic reticulum (ER).

CONCLUSION

We selected preliminary but comprehensive data about differential expression protein spots of LOVO cell. Among these, the five interesting differential expression protein spots identified in this study may provide new insight into LOVO cell therapeutic biomarkers. Curcumin may suppress GSTM5 expression to enhance the lethal effect of irinotecan on LOVO cells, and maybe their combination via the affection of PDI and PRDX4 to disturb the formation and reduction of disulfides results in inducing apoptosis of LOVO cell.

Withdrawal reaction of carbamazepine after neurovascular decompression for trigeminal neuralgia: a preliminary study

OBJECTIVE

To evaluate the representations and the relevant factors of carbamazepine-associated withdrawal reaction (CAWR) after microvascular decompression (MVD) to treat trigeminal neuralgia (TN).

METHODS

The present series included 90 patients who were referred from September 2010 to January 2013 and diagnosed with classical TN. The carbamazepine (CBZ) serum level was tested twice at 24h pre- and 24h post-operation by using HPLC analysis. The analysis of correlating selected factors and CAWR was performed.

RESULTS

Among 90 patients, 26 (28.9%) suffered from post-operative CAWR for 3 days after MVD. The symptoms of CAWR include overexcitement, e.g. insomnia, dysphoria, hand fremitus, hallucination and severe headache. The history of CBZ therapy before MVD, pre-operative dosage of CBZ, and the D-value of CBZ blood concentrations demonstrated statistic differences between the patients with CAWR and those without CAWR. Patient characteristics such as gender, age, and duration of neuralgia, neuralgia-related factors including neuralgia extent and neurovascular compression severity, and operation conditions including duration of MVD procedure, effect of MVD and complication of MVD had no influence on the occurrence of CAWR.

CONCLUSION

It is strongly suggested that CAWR is dependent on the pre-operative dosage and the changing rate of pre- and post-operative CBZ blood concentrations.

PTEN hypermethylation profiles of Chinese Kazakh patients with esophageal squamous cell carcinoma

Aberrant DNA methylation of promoter region CpG islands may serve as an alternative mechanism to genetic defects in the inactivation of tumor suppressor genes (TSGs) in human malignancies. The aim of this study was to examine the promoter methylation status of the PTEN TSG and its association with esophageal squamous cell carcinoma (ESCC) carcinogenesis in a Chinese Kazakh population, which is known to have a relatively high ESCC incidence and mortality. The methylation status of the PTEN promoter region was determined in patients with ESCC (n = 95) and healthy individuals (n = 65) using highly sensitive Sequenom Epityper assays. The methylation level of the PTEN gene was significantly higher in patients with ESCC than in healthy controls. The median methylation level was 10.0% (interquartile range [IQR]: 7.0-11.0%) in patients with ESCC and 6.0% in controls (IQR: 4.0-9.0%; P = 0.001). PTEN methylation levels were higher in male patients with ESCC than in male controls, whereas a trend toward significance was observed between female patients with ESCC and female controls (P = 0.005 and P = 0.086, respectively). The PTEN methylation level was associated with histopathological grade and lymph node metastasis in patients with ESCC (P = 0.002 and P = 0.009, respectively). To our knowledge, this is the first report to show the presence of PTEN promoter CpG hypermethylation in ESCC and its association with tumor metastasis.

Radiofrequency ablation technique in the treatment of liver tumours: review and future issues

Thermal ablation is increasingly being used for treatment of liver tumours. Among the techniques of thermal ablation, radiofrequency ablation (RF) is undoubtedly being used most frequently because of its advantages, such as morbidity and mortality rates, effective tumour ablation, as well as being less time-consuming. This paper presents the state of the art of RF ablation technique. This includes the theoretical development, experimental study and clinical application of the radiofrequency ablation technique. First, it introduces the principle of this technique. Second, it shows the development of this technique and valuable achievements. These achievements include the device, strategy of operation and extension to other diseases. Third, it concludes future issues to be addressed in order to further advance this technique.

Electromagnetic navigation-guided radiofrequency thermocoagulation in trigeminal neuralgia: technical note with three case reports

OBJECTIVE

To introduce our device and procedure of electromagnetic navigation (EMN)-guided radiofrequency thermocoagulation (RFT) in patients with trigeminal neuralgia (TN).

METHODS

The EMN system mainly consists of an electromagnetic localizer, a thermoplastic facial mask with fiducial markers, and navigation software. A new surgical interface in which the foramen ovale (FO) and the trigeminal ganglion (TG) were integrated was used. It was applied in three patients with TN.

RESULTS

FO was successfully and accurately cannulated on the first attempt by using EMN guidance. During the follow-up period, pain did not reoccur, and appropriate trigeminal sensory paresthesia was elicited. There were no surgery-related complications.

CONCLUSION

The EMN system is effective and highly accurate for RFT in patients with primary TN. Our modification of the registration system and surgical interface could make the RFT process more simple and accurate.

Evaluation of energy digestibility and prediction of digestible and metabolizable energy from chemical composition of different cottonseed meal sources fed to growing pigs

The present experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME) content, and the apparent total tract digestibility (ATTD) of energy in growing pigs fed diets containing one of ten cottonseed meals (CSM) collected from different provinces of China and to develop in vitro prediction equations for DE and ME content from chemical composition of the CSM samples. Twelve growing barrows with an initial body weight of 35.2±1.7 kg were allotted to two 6×6 Latin square designs, with six barrows and six periods and six diets for each. A corn-dehulled soybean meal diet was used as the basal diet, and the other ten diets were formulated with corn, dehulled soybean meal and 19.20% CSM. The DE, ME and ATTD of gross energy among different CSM sources varied largely and ranged from 1,856 to 2,730 kcal/kg dry matter (DM), 1,778 to 2,534 kcal/kg DM, and 42.08 to 60.47%, respectively. Several chemical parameters were identified to predict the DE and ME values of CSM, and the accuracy of prediction models were also tested. The best fit equations were: DE, kcal/kg DM = 670.14+31.12 CP+659.15 EE with R² = 0.82, RSD = 172.02, p<0.05; and ME, kcal/kg DM = 843.98+25.03 CP+673.97 EE with R² = 0.84, RSD = 144.79, p<0.05. These results indicate that DE, ME values and ATTD of gross energy varied substantially among different CSM sources, and that some prediction equations can be applied to predict DE and ME in CSM with an acceptable accuracy.

Loss of SNAIL regulated miR-128-2 on chromosome 3p22.3 targets multiple stem cell factors to promote transformation of mammary epithelial cells

A discontinuous pattern of LOH at chromosome 3p has been reported in 87% of primary breast cancers. Despite the identification of several tumor suppressor genes in this region, there has yet to be a detailed analysis of noncoding RNAs including miRNAs in this region. In this study, we identified 16 aberrant miRNAs in this region and determined several that are frequently lost or amplified in breast cancer. miR-128-2 was the most commonly deleted miRNA. Embedded in the intron of the ARPP21 gene at chromosome 3p22.3, miR-128-2 was frequently downregulated along with ARPP21 in breast cancer, where it was negatively associated with clinicopathologic characteristics and survival outcome. Forced expression of miR-128 impeded several oncogenic traits of mammary carcinoma cells, whereas depleting miR-128-2 expression was sufficient for oncogenic transformation and stem cell-like behaviors in immortalized nontumorigenic mammary epithelial cells, both in vitro and in vivo. miR-128-2 silencing enabled transforming capacity partly by derepressing a cohort of direct targets (BMI1, CSF1, KLF4, LIN28A, NANOG, and SNAIL), which together acted to stimulate the PI3K/AKT and STAT3 signaling pathways. We also found that miR-128-2 was directly downregulated by SNAIL and repressed by TGF-β signaling, adding 2 additional negative feedback loops to this network. In summary, we have identified a novel TGF-β/SNAIL/miR-128 axis that provides a new avenue to understand the basis for oncogenic transformation of mammary epithelial cells.

Inference of biological S-system using the separable estimation method and the genetic algorithm

Reconstruction of a biological system from its experimental time series data is a challenging task in systems biology. The S-system which consists of a group of nonlinear ordinary differential equations (ODEs) is an effective model to characterize molecular biological systems and analyze the system dynamics. However, inference of S-systems without the knowledge of system structure is not a trivial task due to its nonlinearity and complexity. In this paper, a pruning separable parameter estimation algorithm (PSPEA) is proposed for inferring S-systems. This novel algorithm combines the separable parameter estimation method (SPEM) and a pruning strategy, which includes adding an l₁ regularization term to the objective function and pruning the solution with a threshold value. Then, this algorithm is combined with the continuous genetic algorithm (CGA) to form a hybrid algorithm that owns the properties of these two combined algorithms. The performance of the pruning strategy in the proposed algorithm is evaluated from two aspects: the parameter estimation error and structure identification accuracy. The results show that the proposed algorithm with the pruning strategy has much lower estimation error and much higher identification accuracy than the existing method.

Construction and evaluation of high-quality n-ZnO nanorod/p-diamond heterojunctions

Vertically-aligned ZnO nanorods (NRs) arrays were synthesized by a low-temperature solution method on boron-doped diamond (BDD) films. The morphology, growth direction, and crystallinity of the ZnO NRs were studied by scanning electron microscopy, X-ray diffraction and cathodoluminescence. Electrical characterization of the ZnO NR/BBD heterostructures revealed characteristic p-n junction properties with an on/off ratio of about 50 at +/- 4 V and a small reverse leakage current approximately 1 microA. Moreover, the junctions showed an ideality factor around 1.0 at a low forward voltage from 0 to 0.3 V and about 2.1 for an increased voltage ranging from 1.2 to 3.0 V, being consistent with that of an ideal diode according to the Sah-Noyce-Shockley theory.

Controlled growth of ZnO/Zn₁-xPbxSe core-shell nanowires and their interfacial electronic energy alignment

ZnO/Zn(1-x)Pb(x)Se core-shell nanowires (NWs) have been synthesized by a solution based surface ion transfer method at various temperatures. The energy dispersive spectroscopic (EDS) mapping of single NWs suggests that the Zn, Pb and Se atoms are uniformly distributed in their shell layers. The ternary Zn(1-x)Pb(x)Se layers with tunable bandgaps extend the band-edge of optical absorption from 450 nm to 700 nm contrasting with the binary ZnSe layers. The ultraviolet photoelectron spectroscopic (UPS) analysis reveals a transition from the type I to type II band alignment when the x fraction decreases from 0.66 to the value of 0.36 in the nanoshell layers. This quantitative investigation of electronic energy levels at ZnO and Zn(1-x)Pb(x)Se interfaces indicates that the proper type II band alignment is well suited for photovoltaic energy conversion. The photovoltaic cells comprising a ZnO/Zn(1-x)Pb(x)Se nano-heterojunction with the optimized Pb content are expected to be more efficient than the devices sensitized by binary ZnSe or PbSe.

Wire network behavior in superconducting Nb films with diluted triangular arrays of holes

We present results of transport measurements on superconducting Nb films with diluted triangular arrays (honeycomb and kagomé) of holes. The patterned films have large disk-shaped interstitial regions even when the edge-to-edge separations between nearest neighboring holes are comparable to the coherence length. Changes in the field interval of two consecutive minima in the field dependent resistance R(H) curves are observed. In the low field region, fine structures in the R(H) and T(c)(H) curves are identified in both arrays. Comparison of experimental data with calculation results reveals that these structures observed in honeycomb and kagomé hole arrays resemble those in wire networks with triangular and T(3) symmetries, respectively. The findings suggest that even in these specified periodic hole arrays with very large interstitial regions, the low field fine structures are determined by the connectivity of the nanostructures.

[Flow cytometric monitoring of minimal residual diseases in patients with acute leukemia after allogeneic hemapoietic stem cell transplantation]

OBJECTIVE

To study the significance of flow cytometric monitoring minimal residual diseases (MRD) in patients with acute leukemia (AL) after allogeneic hemapoietic stem cell transplantation (HSCT).

METHODS

From January 2007 and January 2008 MRD were detected by flow cytometry (FCM) in 402 bone marrow (BM) in 102 AL patients without leukemic gene and chromosomal changes at first diagnosis after HSCT (1, 2, 3, 6,12 months after HSCT; adding detection frequency in part of high risk patients), The relationship between the MRD results and clinical prognosis were observed. Patients with significantly higher MRD were treated and the effectiveness was monitored by FCM (MRD > 0.01% considered as positive).

RESULTS

(1) 71 cases were persistently negative for MRD after HSCT and all them were in hematologic complete remission (CR). Only 3 cases had extramedullary relapse. The disease free survival (DFS) and overall survival (OS) were 66.2% and 90.1%, respectively. (2) Of 27 MRD(+) cases 11 converted to MRD negativity after chemotherapy plus donor lymphocyte infusion (DLI), CIK, NK cells. The DFS and OS were 63.6% and 72.7%, respectively. Other 16 cases had hematologic relapse. The DFS and OS were 11.1% and 25.0%, respectively. The median time from MRD increasing to hematologic relapse was 48 days (7-69 day). (3) Four cases had hematologic relapse after HSCT and died in the end.

CONCLUSIONS

(1) The DFS and the OS in MRD(-) cases are significantly higher than those of MRD(+) cases. (2)MRD(+) patients after HSCT coveted to MRD(-) after intervention. Therapy, whose DFS and the OS are still significantly higher than those of MRD(+) cases. (3) Patients with hematologic relapse after HSCT have the worst prognosis and the DFS and OS are significantly low. FCM monitoring of MRD in patients after HSCT is a sensitive, specific, quick and simple method. It can indicate recurrent state in time, facilitates early intervention, reduces the hematologic relapse risk and improves DFS.

Note: Optimization of piezoresistive response of pure carbon nanotubes networks as in-plane strain sensors

The use of carbon nanotubes (CNT) for the application in in-plane strain detection is promising. In recent years, in-plane strain sensors constructed from CNT networks have been developed; however, few studied optimization of these sensors. In this paper, a study of the optimization of pure CNT networks in terms of piezoresistive response is reported. The so-called pure CNT networks are CNT networks free of surfactants. The performances of piezoresistive response are gauge factor (GF) and linearity. The variables are the number of layers of networks, concentration of CNT solution, and length of sonication time. As a result, the study concluded an optimal pure CNT networks sensor (GF: 2.59, linearity 0.98) with ten layers of networks, 0.8 mg/ml concentration, and 2 h of sonication time.

An expert support system for breast cancer diagnosis using color wavelet features

Breast cancer diagnosis can be done through the pathologic assessments of breast tissue samples such as core needle biopsy technique. The result of analysis on this sample by pathologist is crucial for breast cancer patient. In this paper, nucleus of tissue samples are investigated after decomposition by means of the Log-Gabor wavelet on HSV color domain and an algorithm is developed to compute the color wavelet features. These features are used for breast cancer diagnosis using Support Vector Machine (SVM) classifier algorithm. The ability of properly trained SVM is to correctly classify patterns and make them particularly suitable for use in an expert system that aids in the diagnosis of cancer tissue samples. The results are compared with other multivariate classifiers such as Naïves Bayes classifier and Artificial Neural Network. The overall accuracy of the proposed method using SVM classifier will be further useful for automation in cancer diagnosis.

[Analyze and compare activities of polysaccharide form rhizoma chuanxiong and radix paeoniae rubra]

OBJECTIVE

To explore the difference of biological activities between two Chinese Herbs polysaccharides.

METHODS

Extracted two kinds of Chinese Herbs Polysaccharides by hot water, and determined the content of Polysaccharides. Determined the antibacterial activity with turbidimetry. Explored antioxidant activity using an in vitro antioxidant analysis, probed into the effects on cell growth with MTT colorimetric analysis.

RESULTS

The two polysaccharides both showed activities on the antibacterial, anti-oxidation and promotion of cell growth but different in degree. The Radix Paeoniae Rubra polysaccharide was stronger than Rhizoma Chuanxiong in antioxidant and antimicrobial activities, and weaker in promotion of cell growth activity.

CONCLUSION

Activity differences exist between the two polysaccharides and the activities show some complementary effects. The differences provide important value in research on polysaccharide compound.

Surface nanostructuring of boron-doped diamond films and their electrochemical performance

Uniform and vertically aligned nanocone and nanopillar arrays were successfully constructed on heavily boron-doped nanocrysatlline diamond films by carrying out bias-assisted reactive ion etching in hydrogen/argon plasmas. The electrochemical properties of the nanostructured boron-doped diamond films were investigated by cyclic voltammetry using 1 mM [Fe(CN)6](3-/4-) as redox couple. Compared to the planar boron-doped nanocrystalline diamond film electrode, the surface nanostructuring of boron-doped diamond film electrodes demonstrate enhanced sensitivity due to their enlarged electro-active surface areas. The results indicated that boron-doped diamond nanocones and nanopillars are promising electrode materials which benefit to improve the efficiency, sensitivity and reproducibility of biomedical and chemical sensors.

Ectopic study of tissue-engineered bone complex with enamel matrix proteins, bone marrow stromal cells in porous calcium phosphate cement scaffolds, in nude mice

OBJECTIVE

This study aimed to investigate the potential of enamel matrix proteins (EMPs) on promoting osteogenic differentiation of porcine bone marrow stromal cells (pBMSCs), as well as new bone formation capabilities, in a tissue-engineered bone complex scaffold of EMPs, pBMSCs and porous calcium phosphate cement (CPC).

MATERIALS AND METHODS

Effects of EMPs on pBMSCs in vitro was first determined by alkaline phosphatase (ALP) activity, von Kossa staining assay and mRNA expression of ALP, bone sialoprotein (BSP) and osteocalcin (OCN) genes. Next, an ectopic new bone formation test was performed in a nude mouse model with four groups: CPC scaffold alone; CPC scaffold + EMPs; CPC scaffold + pBMSCs; and CPC scaffold + EMPs + pBMSCs, for 2 or 4 weeks.

RESULTS

ALP activity, von Kossa assay and mRNA expressions of ALP, BSP and OCN genes were all significantly higher with 150 μg/ml EMP treatment in vitro. In nude mice, new bone formation was detected only in the CPC scaffold + EMPs + pBMSCs group at 2 weeks. At 4 weeks, in the tissue-engineered construct there was significantly higher bone formation ability than other groups.

CONCLUSIONS

EMPs promoted osteogenic differentiation of pBMSCs, and the tissue-engineered complex of EMPs, pBMSCs and CPC scaffold may be a valuable alternative to be used in periodontal bone tissue engineering and regeneration.

Single-crystalline ZnTe nanowires for application as high-performance green/ultraviolet photodetector

Single-crystalline ZnTe nanowires were prepared by a simple vapor transport and deposition method. Photodetectors of individual ZnTe nanowires were fabricated to study photoconductivity of the nanowires. It was observed the nanowire photodetectors show the highest visible-light photoconductive gains among all reported photodetectors based on 1D nanostructure semiconductors, including CdS, CdSe, ZnSe, etc. The high photosensitivity and relatively fast response speed are attributable to the high crystal quality of the ZnTe nanowires. These results reveal that such single-crystalline ZnTe nanowires are excellent candidates for optoelectronic applications.

Investigations of mechanical vibrations for beamlines at the Canadian Light Source

Vibration is often a problem causing poor quality of photon beams at synchrotron radiation facilities, since beamlines are quite sensitive to vibrations. Therefore, vibration analysis and control at synchrotron radiation facilities is crucial. This paper presents investigations on mechanical vibrations at four beamlines and endstations at the Canadian Light Source, i.e. the Canadian Macromolecular Crystallography Facility 08ID-1 beamline, the Hard X-ray MicroAnalysis 06ID-1 beamline, the Resonant Elastic and Inelastic Soft X-ray Scattering 10ID-2 beamline, and the Scanning Transmission X-ray Microscope endstation at the Spectromicroscopy 10ID-1 beamline. This study identifies vibration sources and investigates the influence of mechanical vibrations on beamline performance. The results show that vibrations caused by movable mechanical equipment significantly affect the data acquired from beamlines.

Modeling material-degradation-induced elastic property of tissue engineering scaffolds

The mechanical properties of tissue engineering scaffolds play a critical role in the success of repairing damaged tissues/organs. Determining the mechanical properties has proven to be a challenging task as these properties are not constant but depend upon time as the scaffold degrades. In this study, the modeling of the time-dependent mechanical properties of a scaffold is performed based on the concept of finite element model updating. This modeling approach contains three steps: (1) development of a finite element model for the effective mechanical properties of the scaffold, (2) parametrizing the finite element model by selecting parameters associated with the scaffold microstructure and/or material properties, which vary with scaffold degradation, and (3) identifying selected parameters as functions of time based on measurements from the tests on the scaffold mechanical properties as they degrade. To validate the developed model, scaffolds were made from the biocompatible polymer polycaprolactone (PCL) mixed with hydroxylapatite (HA) nanoparticles and their mechanical properties were examined in terms of the Young modulus. Based on the bulk degradation exhibited by the PCL/HA scaffold, the molecular weight was selected for model updating. With the identified molecular weight, the finite element model developed was effective for predicting the time-dependent mechanical properties of PCL/HA scaffolds during degradation.

[Successful treatment of high risk/refractory leukemia by tumor-ablative individualized conditioning allogeneic hematopoietic stem cell transplantation]

OBJECTIVE

To explore the efficacy of tumor-ablative individualized allogeneic hematopoietic stem cell transplantation for the treatment of patients with high risk/refractory leukemia.

METHODS

Fivety-seven patients with high risk/refractory leukemia were enrolled. Tumor-ablative individualized conditioning regimens included HDAra-C + Bu/Cy, Ara-C + Bu/Fludarabine, G-CSF primed HDAra-C + Bu/Cy, and FLAG followed by reduced-intensified BuCy. Overall survival (OS), disease free survival (DFS), graft versus host disease, infection and relapse post grafting were analyzed.

RESULTS

Fifty-six patients attained durable engraftment. The median follow-up duration was 17.5 (2 - 34) months. The 18 months probabilities of OS and DFS were (74.7 ± 6.1)% and (62.4 ± 6.7)%, respectively. In addition, the 18 months probabilities of OS and DFS in patients who attained complete remission (CR) before transplantation were (74.2 ± 7.1)% and (58.8 ± 8.1)%, respectively, while in those not attained CR were (77.0 ± 11.8)% and (72.7 ± 11.7)%, respectively. Twenty nine patients developed acute GVHD (aGVHD) (grade I in 18, grade II in 4, grade III in 2 and grade IV in 5). The probabilities of aGVHD was (50.9 ± 6.6)% by Kaplan-Meier curve analysis. The probabilities of grades 2-4 and grades 3-4 aGVHD were (19.3 ± 5.2)% and (12.3 ± 4.3)% respectively. Extensive chronic GVHD (cGVHD) was observed in 36 patients. The probabilities of cGVHD was (64.3 ± 6.4)% by Kaplan-Meier curve analysis. Cytomegaloviremia (CMV) was observed in 39 (68.42%) patients, hemorrhagic cystitis in 13 (22.8%) patients, fungous infection in 16 (28.07%) patients and bacterial infection in 38 (66.67%) patients. Relapse occurred in 14 patients (hematologic relapse in 11 and extramedullary relapse in 3), probabilities of relapse being (24.6 ± 5.7)%. The 17.5-month probability of relapse in patients who attained CR before transplantation was (28.1 ± 7.7)%, while in those not attained CR was (15.6 ± 10.2)%. Fifteen patients died (6 from hematological relapse, 5 from infection of bacterial and fungous, 4 from cGVHD) after 100 days.

CONCLUSION

Tumor-ablative individualized allogeneic hematopoietic stem cell transplantation is a promising and safe choice for treatment of high risk/refractory leukemia, even with high leukemia burden.

Tunable electrical properties of silicon nanowires via surface-ambient chemistry

p-Type surface conductivity is a uniquely important property of hydrogen-terminated diamond surfaces. In this work, we report similar surface-dominated electrical properties in silicon nanowires (SiNWs). Significantly, we demonstrate tunable and reversible transition of p(+)-p-i-n-n(+) conductance in nominally intrinsic SiNWs via changing surface conditions, in sharp contrast to the only p-type conduction observed on diamond surfaces. On the basis of Si band energies and the electrochemical potentials of the ambient (pH value)-determined adsorbed aqueous layer, we propose an electron-transfer-dominated surface doping model, which can satisfactorily explain both diamond and silicon surface conductivity. The totality of our observations suggests that nanomaterials can be described as a core-shell structure due to their large surface-to-volume ratio. Consequently, controlling the surface or shell in the core-shell model represents a universal way to tune the properties of nanostructures, such as via surface-transfer doping, and is crucial for the development of nanostructure-based devices.

Design and recombinant expression of insulin-like peptide 5 precursors and the preparation of mature human INSL5

Insulin-like peptide 5 (INSL5) is a recently identified insulin superfamily member. Although it binds to and activates the G-protein coupled receptor, RXFP4, its precise biological function remains unknown. To help determine its function, significant quantities of INSL5 are required. In the present work, three single-chain INSL5 precursors were designed, two of which were successfully expressed in E. coli cells. The expressed precursors were solubilized from inclusion bodies, purified almost to homogeneity by immobilized metal-ion affinity chromatography, and then refolded in vitro. One precursor could be converted to two-chain human INSL5 bearing an extended N-terminus of the A-chain (designated long-INSL5) by sequential Lys-C endoproteinase and carboxypeptidase B treatment. The 6 residue A-chain N-terminal extension of long-INSL5 was subsequently removed by Aeromonas aminopeptidase to yield native INSL5 that was designated short-INSL5. Circular dichroism spectroscopic analysis and peptide mapping showed that the recombinant INSL5s adopted an insulin-like conformation and possessed the expected characteristic insulin-like disulfide linkages. Activity assay showed that both long- and short-INSL5 had full RXFP4 receptor activity compared with chemically synthesized human INSL5. This suggested that extension of the N-terminus of the A-chain of long-INSL5 did not adversely impact upon the binding to or activation of the RXFP4 receptor. However, the single-chain INSL5 precursor was inactive which indicated that a free C-terminus of the B-chain is critical for the activity of INSL5. Our present work thus provides an efficient approach for preparation of INSL5 and its analogs through recombinant expression in E. coli cells.