Expression of hexokinase 2 in epithelial ovarian tumors and its clinical significance in serous ovarian cancer

"Warburg effect" emphasizes that malignant cells exhibit active glycolysis even under aerobic conditions. Hexokinase 2 (HK2) is a key glycolytic enzyme that helps to exhibit a "Warburg effect". In the present study, the main aim was to detect the expression of HK2 in epithelial ovarian tumor tissues. Immunohistochemistry and qRT-PCR were used to examine the expression of HK2 in different epithelial ovarian tissues. The expression of HK2 in ovarian cancer tissues was significantly higher than that in normal ovarian, benign, and borderline tumors both in protein (p < 0.001) and mRNA (p < 0.05) levels. HK2 expression was significantly higher in Stage III/IV compared to Stage III (p < 0.001). Expression of HK2 in poorly-differentiated carcinoma was higher than that in well-differentiated carcinoma (p = 0.008). The level of HK2 was higher in serous groups than in non-serous groups in both protein (p = 0.008) and mRNA (p < 0.05) level. Collectively, HK2 is highly expressed in epithelial ovarian cancer, especially in serous groups. Its expression is related with clinical stage and histological differentiation.

Triptolide induces apoptosis in human leukemia cells through caspase-3-mediated ROCK1 activation and MLC phosphorylation

The diterpene triepoxide triptolide is a major active component of Tripterygium wilfordii Hook F, a popular Chinese herbal medicine with the potential to treat hematologic malignancies. In this study, we investigated the roles of triptolide in apoptosis and cell signaling events in human leukemia cell lines and primary human leukemia blasts. Triptolide selectively induced caspase-dependent cell death that was accompanied by the loss of mitochondrial membrane potential, cytochrome c release, and Bax translocation from the cytosol to the mitochondria. Furthermore, we found that triptolide dramatically induced ROCK1 cleavage/activation and MLC and MYPT phosphorylation. ROCK1 was cleaved and activated by caspase-3, rather than RhoA. Inhibiting MLC phosphorylation by ML-7 significantly attenuated triptolide-mediated apoptosis, caspase activation, and cytochrome c release. In addition, ROCK1 inhibition also abrogated MLC and MYPT phosphorylation. Our in vivo study showed that both ROCK1 activation and MLC phosphorylation were associated with the tumor growth inhibition caused by triptolide in mouse leukemia xenograft models. Collectively, these findings suggest that triptolide-mediated ROCK1 activation and MLC phosphorylation may be a novel therapeutic strategy for treating hematological malignancies.

IQGAP1 plays an important role in the cell proliferation of multiple myeloma via the MAP kinase (ERK) pathway

The present study was designed to explore the role of IQ motif-containing GTPase activating protein 1 (IQGAP1) in the cell proliferation of multiple myeloma (MM) via the MAP kinase (ERK) pathway. Reverse transcription‑polymerase chain reaction (RT-PCR) and western blot analysis were carried out to evaluate the expression of IQGAP1 in RPMI8226, U266 and KM3 cell lines and in primary MM cells from 4 MM patients. shRNA-expressing plasmids were used in RPMI8226 cells to knock down IQGAP1 and an MTT assay was used to examine the proliferative activity of the RPMI8226-shIQGAP1 (clone 1), RPMI8226-shRNA negative and untransfected RPMI8226 cells in subgroups stimulated with VEGF/IL-6 or without. Western blot analyses were then performed to examine the protein levels of p-ERK1/2, ERK1/2, AKT, p-AKT, STAT3, p-STAT3 in the RPMI8226-shIQGAP1 (clone 1), RPMI8226-shRNA negative and untransfected RPMI8226 cells. Co-immunoprecipitation was used to verify the interaction between the IQGAP1 scaffold and the MAP ERK kinase. We found that IQGAP1 was overexpressed in the human myeloma cell lines and in the patient MM cells. The proliferation rate in the RPMI8226 cells was decreased when IQGAP1 was knocked down with shRNA. IQGAP1 was found to affect RPMI8226 cell proliferation by regulation of the MAP kinase (ERK1/2) pathway; IQGAP1 scaffold-MAP kinase (ERK) interaction was noted in the human myeloma RPMI8226 cell lines. In conclusion, IQGAP1 plays an important role in the cell proliferation of MM via the MAP kinase (ERK) pathway.

Safety and effectiveness of repeat arterial closure using the StarClose vascular closure device in patients with hepatic malignancy

AIM

To evaluate the safety and effectiveness of the use of the StarClose vascular closure device for repeat arterial closure in patients with hepatic malignancy undergoing transarterial chemoembolization (TACE).

MATERIALS AND METHODS

A retrospective analysis of patients with hepatic malignancy who had undergone arterial closure with the StarClose device was performed in Peking Union Medical College Hospital between January 2009 and March 2012. A total of 165 patients (94 men, 71 women; mean age 60.1 ± 17.2 years) had arterial puncture closure after TACE (using a 5 F sheath). Percutaneous closure of the common femoral artery with the StarClose device was performed in accordance with the manufacturer's recommendations. The patients were examined for complications on follow-up. Device success was defined as haemostasis achieved immediately after StarClose device deployment with or without applying 3 min or less of manual compression. All the patients were evaluated clinically for wound complications and follow-up angiograms of the puncture site were obtained at subsequent TACE sessions.

RESULTS

There were a total of 593 closures using StarClose devices in 165 patients who underwent TACE, including 194 (32.7%) single closures and 399 (67.3%) repeat closures for the same femoral access. The number of repeat closures for the same femoral access ranged from one to nine (median 2). Haemostasis was achieved in 571 closures, and success rate was 96.3% (96.9% in single closures and 96% in repeat closures). There was no statistically different haemostasis success rate between single closures or repeat closures. No severe complications occurred during follow-up.

CONCLUSION

The repeat use of the StarClose device is safe and effective in patients with hepatic malignancy undergoing TACE.

Low loss coupling to sub-micron thick rib and nanowire waveguides by vertical tapering

Highly nonlinear planar glass waveguides have been shown to be useful for all optical signal processing. However, the typical SMF-28 fiber to waveguide coupling loss of ~5dB/end remains a barrier to practical implementation. Low loss coupling to a fiber using vertical tapering of the waveguide film is analyzed for rib and nanowire waveguides and experimentally demonstrated for ribs showing polarization and wavelength independence over >300nm bandwidth. Tapers with essentially zero excess loss led to total losses from the waveguide to fiber core of 1.1dB per facet comprising only material absorption (0.75dB) and mode overlap loss (0.36dB), both of which can be eliminated with improvements to processing and materials.

Anorectal function after partial intersphincteric resection in ultra-low rectal cancer

AIM

To investigate the feasibility and efficacy of intersphincteric resection (ISR), in terms of postoperative anorectal function, for ultra-low rectal cancer in mainland China.

METHOD

A total of 43 patients who consecutively underwent curative partial ISR for ultra-low rectal cancer between 2006 and 2009 were enrolled in the study. Defaecatory function was assessed, using detailed questionnaires, 3, 6 and 12 months after surgery. The Wexner score was used to assess faecal continence, and anal manometry studies were performed to analyse anal sphincter function.

RESULTS

Overall defaecatory function was assessed as being satisfactory in 41 of 43 patients. Twelve months after surgery, the mean Wexner score was 4.0 ± 3.6. Anal manometry studies showed a significant change at 3 months and further, gradual, improvement over the following year. During the postoperative period, maximum squeeze pressure reached a normal value of 174.1 ± 19.5 mmHg (P = 0.041) by 6 months and resting pressure was 42.4 ± 5.6 mmHg by 12 months, which was close to the preoperative level (P = 0.038).

CONCLUSION

Because of the satisfactory recovery of defaecatory function and good oncological results, partial ISR may be recommended as an effective sphincter-preserving operation for patients with ultra-low rectal cancer.

γ-Aminobutyric acid (GABA) signalling in human pancreatic islets is altered in type 2 diabetes

AIMS/HYPOTHESIS

γ-Aminobutyric acid (GABA) is a signalling molecule in the interstitial space in pancreatic islets. We examined the expression and function of the GABA signalling system components in human pancreatic islets from normoglycaemic and type 2 diabetic individuals.

METHODS

Expression of GABA signalling system components was studied by microarray, quantitative PCR analysis, immunohistochemistry and patch-clamp experiments on cells in intact islets. Hormone release was measured from intact islets.

RESULTS

The GABA signalling system was compromised in islets from type 2 diabetic individuals, where the expression of the genes encoding the α1, α2, β2 and β3 GABA(A) channel subunits was downregulated. GABA originating within the islets evoked tonic currents in the cells. The currents were enhanced by pentobarbital and inhibited by the GABA(A) receptor antagonist, SR95531. The effects of SR95531 on hormone release revealed that activation of GABA(A) channels (GABA(A) receptors) decreased both insulin and glucagon secretion. The GABA(B) receptor antagonist, CPG55845, increased insulin release in islets (16.7 mmol/l glucose) from normoglycaemic and type 2 diabetic individuals.

CONCLUSIONS/INTERPRETATION

Interstitial GABA activates GABA(A) channels and GABA(B) receptors and effectively modulates hormone release in islets from type 2 diabetic and normoglycaemic individuals.

An analytical calculation of the fluid load support fraction in a biphasic material: an alternative technique

Background

The fluid load support fraction (W^F/W^T) can be used to define the mechanical contribution of the interstitial fluid (W^F) to the total force (W^T) in the deformation of cartilage. Traditionally, W^F/W^T is calculated using complex experimental setups or time-consuming micromechanical poroelastic Finite Element (FE) simulations.

Aim

To define and validate a fast and efficient technique to predict W^F/W^T using an analytical approach that can be applied without micromechanical detail or experimental measurement.

Methodology

Poroelastic FE simulations defined accurate values of W^F/W^T for a range of loading configurations and were used to validate subsequent predictions. The analytical prediction of W^F/W^T used elastic contact mechanics to calculate W^F, and viscoelastic FE representation to calculate W^T. Subsequently, these independent calculations of W^F and W^T provided values of W^F/W^T that were compared with the poroelastic FE calculations.

Results and discussion

The analytical prediction of W^F/W^T proved effective and suitably accurate (mean difference S<0.05). This technique demonstrated how W^F and W^T can be determined independently, without a biphasic constitutive model. Here we used viscoelasticity to calculate W^T as an example, however, W^T could be measured experimentally or predicted computationally.

Spin-lattice relaxation rates and water content of freeze-dried articular cartilage

OBJECTIVE

Nuclear magnetic resonance (NMR) spin-lattice relaxation rates were measured in bovine and porcine articular cartilage as a function of water content.

METHODS

Water content was varied by freeze-drying samples for short periods of time (up to 15 min). The samples were weighed at all stages of drying so that water content could be quantified. Spin-lattice relaxation rates were measured using magnetic resonance imaging (MRI).

RESULTS

Linear correlations were observed between relaxation rate and two measures of inverse water content: (1) solid-to-water ratio (ρ), expressed as a ratio of the mass of the solid component of the cartilage (m(s)) and the mass of water at each freeze-drying time point (m(w)), and (2) a ratio of the total mass of the fully-hydrated cartilage and m(w) (1/w). These correlations did not appear significantly different for the bovine and porcine data. However, fitting the data to a piecewise-linear model revealed differences between these two species. We interpret the first two segments of the piecewise model as the depletion of different water phases but conjecture that the third segment is partially caused by changes in relaxation rates as a result of a reduction in macromolecular mobilities.

CONCLUSIONS

Whilst we can produce linear correlations which broadly describe the dependence of the measured spin-lattice relaxation rate on (inverse) water content, the linear model seems to obscure a more complicated relationship which potentially provides us with more information about the structure of articular cartilage and its extracellular water.

Efficacy and safety of embolization in iatrogenic traumatic uterine vascular malformations

AIM

To retrospectively evaluate the efficacy of embolotherapy in patients with iatrogenic traumatic uterine arteriovenous malformations (AVMs).

MATERIALS AND METHODS

A retrospective review of all patients who underwent uterine arterial embolization in Peking Union Medical College Hospital between January 2000 and December 2010 was performed. Forty-two patients were diagnosed with a uterine vascular malformation. All patients had obstetric manipulations before. Serial beta-human chorionic gonadotropin (β-HCG) levels were measured to exclude gestational trophoblastic neoplasia. All patients underwent transcatheter embolization of bilateral uterine arteries. The complications, control of haemorrhage, and outcome of subsequent pregnancies were assessed.

RESULTS

A total of 49 embolization procedures were performed in 42 patients. Seven patients required repeated embolizations for recurrence of bleeding. The technical success rate of embolization was 100%. Bleeding was controlled in 35 of 42 patients (83%) after the first embolization procedures, and bleeding was controlled in another two patients who underwent repeat embolization at a median follow-up of 29 months (range 3 months to 5 years). The overall clinical success rate was 88% (37/42). Thirteen patients subsequently became pregnant and eight of 13 patients had uneventful intrauterine pregnancies carried to term. Seven patients had post-embolization syndrome and no other complication occurred.

CONCLUSION

Percutaneous embolotherapy is a safe and effective treatment for traumatic AVMs. Future pregnancy is still possible after embolization.

Tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV/m field strength can be achieved by using appropriate grating parameters.

Analysis of altered proteins related to blast crisis in chronic myeloid leukemia by proteomic study

INTRODUCTION

Chromic myeloid leukemia (CML) blast crisis (BC) and imatinib (IM) resistance is a significant barrier to the effective treatment of the disease.

METHODS

Expression profiles of differential proteins were identified, and new biomarkers or pathways related to BC in CML were screened through proteomic analysis. Total proteins from primary bone marrow cells of CML patients in chronic phase (CP) and BC were separated via two-dimensional (2D) polyacrylamide gel electrophoresis and then analyzed by imagemaster 5.0 software to detect differential protein spots which were already identified by mass spectrometry. Based on the variation of the whole expression profile, some key proteins were picked out for Western blot to confirm the accuracy of proteomics data. Moreover, related signal pathways involving those proteins were investigated.

RESULTS

The result indicated that thirteen protein points between CML-CP and CML-BC were successfully determined. Results from Western blot of RhoA, hnRNPK, ANXA1, PSMB4, and LTA4H were similar to those from 2D polyacrylamide gel electrophoresis. Most of those proteins were involved in the proteosome pathway and the small G-protein pathway.

CONCLUSION

A group of proteins associated with BC can be obtained and the result of this study might provide clues for further research.

An ABA-binding protein with nucleic acid-binding property

Maize cDNA expression library was screened using the antibodies against ABA-binding proteins (ABBP). From 200 000 separated phage plaques, only one cDNA clone coding for a polypeptide was obtained. It shows 60%-65% homology to the genes of nucleic acid-binding proteins in mammalia. However, about 120 cDNA clones coding maize 17s rRNA were unexpectedly obtained. In view of this, the ABBP purified by ABA affinity chromatography and the antibodies derived from the purified ABBP were examined. It is found that rRNA is indeed present in the ABBP. In addition, the obtained antibodies could recognize RNA as well as ABBP. It is suggested that the ABBP have nucleic acid-binding property and can form a complex with rRNA.

Lysine restriction and realimentation affected growth, blood profiles and expression of genes related to protein and fat metabolism in weaned pigs

To investigate the effects of lysine restriction and subsequent realimentation on growth performance, blood profiles and gene expression of leptin and myostatin, 128 weaned pigs [initial body weight (BW) 6.96 ± 1.07 kg, 26 ± 2 days of age] were randomly allotted to four treatments. The starter diets during the first 2 weeks (P1) contained 100%, 80%, 70% or 60% of recommended lysine levels (National Research Council, 1998). Then, common grower 1 and 2 diets were offered for 2 weeks (P2 and P3) each. During P1, average daily gain (ADG) was linearly reduced (p < 0.05) with the increasing levels of lysine restriction. Growth rate was greater in pigs previously fed lysine-restricted diets than well-fed pigs although it did not reach a significant level during realimentation. However, the final BW and overall ADG were the lowest (p < 0.05) and F/G was poor in pigs fed 60% lysine diet. Relative visceral organ weights and composition of skeletal muscle were similar (p > 0.05) among the treatment. Blood triglyceride and glucose levels were increased (p < 0.05) during P1, while blood urine nitrogen, total protein and albumin levels were decreased (p < 0.05) during P2 with the reduction in dietary lysine levels. The abundance of myostatin mRNA in skeletal muscle and leptin mRNA in subcutaneous adipose tissue were lower (p < 0.05) in lysine-restricted pigs than in pigs fed non-restricted diets. In conclusion, 80% and 70% lysine restriction of starter diets resulted in inferior growth and compensatory growth effect was noted during realimentation, while 60% lysine restriction had a negative influence on growth performance. Moreover, the changes in myostatin and leptin mRNA abundance caused by nutritional manipulations may be involved in the regulation of protein and fat deposition in young pigs.

The effect of contact stress on cartilage friction, deformation and wear

Following hip hemiarthroplasty, a metal femoral head articulates against natural acetabular cartilage. Cartilage friction and wear may be influenced by variables including loading time, contact stress, contact area, sliding distance, and sliding speed. The aim of this study was to investigate the effect of these variables on cartilage friction, deformation and wear in a simulation using idealized geometry model. Bovine cartilage pins were reciprocated against metal plates to mimic a hemiarthroplasty articulation under static loading. The effective coefficient of friction (µeff) under contact stresses (0.5 to 16 MPa), contact areas (12 and 64 mm2), stroke lengths (4 and 8 mm), sliding velocities (4 and 8 mm/s), and loading time (1 and 24 hours) were studied. The permanent deformation of cartilage (after 24 hours of recovery) with and without motion was recorded to assess cartilage linear wear.

The µeff was found to remain < 0.35 with contact stresses ≤ 4 MPa. Severe damage to the cartilage occurred at contact stresses > 8 MPa and significantly increased µeff after 12 hours of reciprocation. In long-term, contact area had no significant effect on µeff, and sliding distance and velocity only affected µeff under low contact stresses. The cartilage linear wear increased with contact stress, sliding distance and velocity.

Fabrication of porous beta-tricalcium phosphate with microchannel and customized geometry based on gel-casting and rapid prototyping

The tissue engineering scaffolds with three-dimensional porous structure are regarded to be beneficial to facilitate a sufficient supply of nutrients and enable cell ingrowth in bone reconstruction. However, the pores in scaffolds tend to be blocked by the cell ingrowth and result in a restraint of nutrient supply in the further side of the scaffold. An indirect approach of combining the rapid prototyping and gel-casting technique is introduced in this study to fabricate beta-tricalcium phosphate (beta-TCP) scaffolds which not only have interconnected porous structure, but also have a microchannel network inside. The scaffold was designed with customized geometry that matches the defect area, and a double-scale (micropores-microchannel) porous structure inside that is beneficial for cell ingrowth. The scaffolds fabricated have an open, uniform, and interconnected porous architecture with a pore size of 200-400 microm, and posses an internal channel network with a diameter of 600 microm. The porosity was controllable. The compressive yield strength was 4.5 MPa with a porosity of 70 per cent. X-ray diffraction analysis shows that these fabrication processes do not change the crystal structure and chemical composition of beta-TCP. With this technique, it was also possible to fabricate porous scaffolds with desired pore size, porosity, and microchannel, as well as customized geometries by other bioceramics.

Konjac glucomannan as a carrier material for time--temperature integrator

Hardness, springiness and water retention of konjac glucomannan gel (g-KGM) as a novel carrier material for time-temperature integrator (TTI) in aseptic processing were determined and compared with those of sodium alginate gel (g-SA). Hardness of both g-KGM and g-SA increased with temperature: values of g-SA were significantly higher (p < 0.05) than those of g-KGM at all temperatures. No significant difference in springiness between g-KGM and g-SA from 40 °C to 90 °C and significant differences (p < 0.05) between 100 °C and 140 °C were found. Water retention property of g-KGM was lower than that of g-SA between 60 °C and 100 °C, but much higher between 100 °C and 140 °C. Heat transfer tests performed on g-KGM alone as well as on g-KGM as a carrier, embedded with TTI, α-amylase as an integrator, indicated that g-KGM was suitable for industrial ultrahigh temperature sterilization test.

The effect of surface finish and interstitial fluid on the cement-in-cement interface in revision surgery of the hip

The mechanical performance of the cement-in-cement interface in revision surgery has not been fully investigated. The quantitative effect posed by interstitial fluids and roughening of the primary mantle remains unclear. We have analysed the strength of the bilaminar cement-bone interface after exposure of the surface of the primary mantle to roughening and fluid interference. The end surfaces of cylindrical blocks of cement were machined smooth (Ra = 200 nm) or rough (Ra = 5 μm) and exposed to either different volumes of water and carboxymethylcellulose (a bone-marrow equivalent) or left dry. Secondary blocks were cast against the modelled surface. Monoblocks of cement were used as a control group. The porosity of the samples was investigated using micro-CT. Samples were exposed to a single shearing force to failure.

The mean failure load of the monoblock control was 5.63 kN (95% confidence interval (CI) 5.17 to 6.08) with an estimated shear strength of 36 MPa. When small volumes of any fluid or large volumes were used, the respective values fell between 4.66 kN and 4.84 kN with no significant difference irrespective of roughening (p > 0.05). Large volumes of carboxymethylcellulose significantly weakened the interface. Roughening in this group significantly increased the strength with failure loads of 2.80 kN (95% CI 2.37 to 3.21) compared with 0.86 kN (95% CI 0.43 to 1.27) in the smooth variant. Roughening of the primary mantle may not therefore be as crucial as has been previously thought in clinically relevant circumstances.

The feasibility of light microscopic measurements of intercellular spaces in squamous epithelium in the lower-esophagus of GERD patients

The study aims to determine whether light microscopy can be used to accurately measure the diameters of intercellular spaces between squamous epithelial cells in the lower esophagus, and whether changes in this outcome measure can be used as a diagnostic marker for gastroesophageal reflux disease (GERD). The study has two parts. Part 1 involves 42 asymptomatic controls and 119 patients with typical symptoms of GERD, including 58 with erosive esophagitis (EE), and 61 patients with nonerosive gastroesophageal reflux disease (NERD). All biopsies were taken from the lower esophagus. All samples were observed using an immersion objective, after which diameters were measured by computer-assisted morphometry. Part 2 involves 61 individuals who were randomly selected from part 1, including 19 controls, 13 with NERD and 29 with EE. Diameter measurements using both light microscopy and transmission electron microscopy (TEM) were performed for samples of 61 individuals. Samples from a total of 61 individuals (31 male, 30 female, mean age 44.3 ± 16.0 years) were observed using both light microscopy and TEM. Both methods showed significant differences between control and disease groups; the outcomes from the two methods had a certain correlation (r = 0.605, P = 0.000). Morphometric analysis of all 161 individuals (83 males, 78 females, mean age 41.4 ± 15.7) showed mean diameters from light microscopy to be 0.58 ± 0.16 µm for controls, 1.07 ± 0.30 µm for NERD, and 1.29 ± 0.20 µm for EE; differences between control and disease groups were significant (P<0.05). The optimal cut-off value from receiver operator characteristic analysis was 0.85 µm. Diagnoses were validated using the combination of symptoms of GERD, endoscopy, and 24 h ambulatory pH monitoring as the gold standard. At the optimal cutoff, sensitivity was 93.3% and specificity was 100%. The diameters of the intercellular spaces in squamous epithelium of lower esophagus from controls and in patients with GERD can be quantitatively measured using light microscopy. Dilated diameters can serve as a sensitive, specific, and objective indicator for diagnosis of GERD.

MicroRNA-192 and -215 are upregulated in human gastric cancer in vivo and suppress ALCAM expression in vitro

The dismal outcome of gastric cancer patients highlights the need for diagnostic biomarkers and effective therapeutic targets, such as microRNAs. We sought to discover microRNAs involved in gastric cancer, and to elucidate their downstream target mechanisms. Both cultured gastric epithelial cells (HFE145 and NCI-N87) and primary human gastric tissues (31 non-neoplastic stomach (NS) and 25 gastric carcinomas (GC)) were studied. MicroRNA microarrays and quantitative RT-PCR were applied to discover and verify differentially expressed microRNAs. in vitro cell migration and invasion, cell proliferation, cell cycle and apoptosis assays were executed to elucidate biological effects of microRNA-192 and -215. Western blotting and luciferase assays were performed to confirm direct messenger RNA targeting by microRNA-192 and -215. MicroRNA microarray analyses revealed that 25 and 20 microRNAs were upregulated and downregulated in GC vs NS, respectively. Expression levels of both microRNA-192 and -215 were significantly higher in GC than in NS (P<0.05). Luciferase assays suggested that microRNA-215 inhibits activated leukocyte cell adhesion molecule (ALCAM) expression at the posttranscriptional level. In addition, expression levels of ALCAM were significantly lower in GC than in NS. Mimics and inhibitors, respectively, of microRNA-192 or -215 exerted no effect on cell cycle or apoptosis in the immortalized normal gastric cell line HFE145 or the gastric cancer cell line NCI-N87. However, mimics of microRNA-192 or -215 significantly increased growth rates in HFE145 cells, whereas inhibitors of microRNA-192 or -215 caused significant decreases in growth rates in NCI-N87 cells. ALCAM knockdown by an ALCAM-specific siRNA significantly increased cell growth in HFE145 cells. Both transfection of mimics of microRNA-192 or -215 and ALCAM knockdown by an ALCAM-specific siRNA significantly increased the migration of HFE145 cells. In conclusion, in gastric cancer, both microRNA-192 and -215 are overexpressed in vivo and exert cell growth and migration-promoting effects in vitro, thus representing potential microRNAs with a role in cancer in the human stomach.

A novel and non-destructive method to examine meniscus architecture using 9.4 Tesla MRI

OBJECTIVE

To investigate the ability of high-field (9.4 T) magnetic resonance (MR) imaging to delineate porcine knee meniscal tissue structure and meniscal tears.

MATERIALS AND METHODS

Porcine knees were obtained from a local abattoir, and eight medial menisci with no visible defects were dissected. Lesions simulating longitudinal tears were created on two of the menisci. MR images of the menisci were obtained at 9.4 T using a three-dimensional (3D)-FLASH sequence. A detailed 3D internal architecture of the intact and injured menisci was demonstrated on high-resolution MR images.

RESULTS

High-resolution 3D MR imaging allowed visualisation of internal architecture of the meniscus and disruption to the internal structural network in damage models. The architecture of the porcine knee meniscus revealed by the MR scans appeared similar to the structures visualised by histology in previously reported studies.

CONCLUSION

High-field MRI is a non-destructive technique to examine the internal structural components and damage/wear of meniscal tissue. It has tremendous potential in the field of functional cartilage/meniscus biomechanics and biotribology.

Two-stage operative cytoreduction and intraperitoneal chemotherapy for diffuse malignant peritoneal mesothelioma: Operative morbidity and mortality in phase I and II trials

AIMS

The standard of care for diffuse malignant peritoneal mesothelioma involves operative cytoreduction and intraperitoneal chemotherapy. Most centers favor aggressive operative cytoreduction, accepting high morbidity and mortality. In our trials, patients underwent less extensive cytoreduction followed by prolonged intraperitoneal chemotherapy. Patients underwent a second cytoreduction with heated intraperitoneal chemotherapy. We hypothesized this would result in lower operative morbidity and mortality with similar survival.

METHODS

Hospital records, discharge summaries, microbiology, radiography, and office records were retrospectively reviewed to supplement a prospective database. 30-day morbidity and mortality were categorized, and classified according to the Clavien methodology.

RESULTS

47 first and 39 second operations were performed with 13% and 26% morbidity, respectively. Mortality was 2%. Infections comprised 59% of the morbidity. Inclusive of both operations, formal peritonectomy was performed in 16% of patients, resection of isolated lesions in less than half, and only 19% had a visceral organs other than the spleen resected. At the completion of the protocol, only 3% of patients had visible intraperitoneal disease. The mean total length of stay for both operations combined was 16 ± 23 days. Overall median survival was 54.9 months, and median survival for the epithelioid subtype was 70.2 months.

CONCLUSIONS

A two-stage cytoreduction with intraperitoneal chemotherapy offers median survival comparable to one-stage protocols, with relatively low morbidity, mortality, visceral resections and length of stay despite two operations. This series supports that our protocol is a feasible and safe approach.

Quasimonoenergetic proton bunch generation by dual-peaked electrostatic-field acceleration in foils irradiated by an intense linearly polarized laser

It is found that stable proton acceleration from a thin foil irradiated by a linearly polarized ultraintense laser can be realized for appropriate foil thickness and laser intensity. A dual-peaked electrostatic field, originating from the oscillating and nonoscillating components of the laser ponderomotive force, is formed around the foil surfaces. This field combines radiation-pressure acceleration and target normal sheath acceleration to produce a single quasimonoenergetic ion bunch. A criterion for this mechanism to be operative is obtained and verified by two-dimensional particle-in-cell simulation. At a laser intensity of ∼5.5×10(22)  W/cm(2), quasimonoenergetic GeV proton bunches are obtained with ∼100  MeV energy spread, less than 4° spatial divergence, and ∼50% energy conversion efficiency from the laser.

Hourglass cell development in the soybean seed coat

BACKGROUND AND AIMS

Hourglass cells (HGCs) are prominent cells in the soybean seed coat, and have potential use as 'phytofactories' to produce specific proteins of interest. Previous studies have shown that HGCs initiate differentiation at about 9 d post-anthesis (dpa), assuming their characteristic morphology by 18 dpa. This study aims to document the structural changes in HGCs during this critical period, and to relate these changes to the concurrent development of a specific soybean peroxidase (SBP) encoded by the Ep gene.

METHODS

Pods were collected from plants at specific growth stages. Fresh material was processed for analysis of Ep peroxidase activity. Tissues were processed for scanning and transmission electron microscopy, as well as extracted for western blotting. A null variety lacking expression of Ep peroxidase was grown as a control.

KEY RESULTS AND CONCLUSIONS

At 9 dpa, HGCs are typical undifferentiated plant cells, but from 12-18 dpa they undergo rapid changes in their internal and external structure. By 18 dpa, they have assumed the characteristic hourglass shape with thick cell walls, intercellular air spaces and large central vacuoles. By 45 dpa, all organelles in HGCs have been degraded. Additional observations indicate that plasmodesmata connect all cell types. SBP activity and SBP protein are detectable in the HGC before they are fully differentiated (approx. 18 dpa). In very early stages, SBP activity appears localized in a vacuole as previously predicted. These results increase our understanding of the structure and development of the HGC and will be valuable for future studies aimed at protein targeting to components of the HGC endomembrane systems.

A New Formulation for the Prediction of Polyethylene Wear in Artificial Hip Joints

Artificial joints employing ultra-high molecular weight polyethylene (UHMWPE) are widely used to treat joint diseases and trauma. Wear of the polymer bearing surface largely limits the use of these joints in younger and more active patients. Previous studies have shown the wear factor used in Archard's law for the conventional polyethylene to be highly dependent on contact pressure and this has produced variability in experimental data and has constrained the reliability and applicability of previous computational predictions. A new wear law is proposed, based on wear volume being dependent on, and proportional to, the product of the sliding distance and contact area. The dimensionless proportional constant, wear coefficient, which was independent of contact pressure, was determined from a multi-directional pin on plate study. This was used in computational predictions of the wear of the conventional UHMWPE hip joints. The wear of the polyethylene cup was independently experimentally determined in physiological full hip joint simulator studies. The predicted wear rate from the new computational model was generally increased, with an improved agreement with the experimental measurement compared with the previous computational model. It was shown that wear in the UHMWPE hip joints increased as head size and contact area increased. This resulted in a much larger increase in the wear rate as the head size increased, compared with the previous computational model, and is consistent with clinical observations. This new understanding of the wear mechanism in artificial joints using the UHMWPE bearing surfaces, and the improved ability to predict wear independently and to address previously described discrepancies offer new opportunities to optimize design parameters.

The Effect of Stem Structure on Stress Distribution of a Custom-Made Hip Prosthesis

A custom-made hip is essential for the initial stability and longevity which correspond to an optimal stress distribution, since a standard hip cannot always satisfy every patient's need. In order to find out the designing principles of a custom-made hip, a patient's personal features on which the design was based were acquired. In this study, an integrated finite element model of the hip (including ilium, acetabular cup, femoral head, femoral stem, and femur) was created based on the computed tomography (CT) images of this patient. A series model with different stem length, cross-section, and collodiaphyseal angle were analysed under both static and quasi-static loading conditions. Comparing the stress distribution on each part of the hip prosthesis with that of the natural hip before replacement, the optimal stem structure for this patient was found. In addition, the changes of interspace between acetabular cup and femoral head were measured according to dynamic CT images on the healthy side of this patient during a gait cycle. Results correspond to the trail of the maximum contact stress sites, which were mainly located on the superolateral surface of the acetabular cup. This custom-design method can also be adopted for other patients.

Association of the genetic polymorphisms of the ACE gene and the eNOS gene with lupus nephropathy in northern Chinese population

BACKGROUND

It has been reported that some single nucleotide polymorphisms (SNPs) of the angiotensin converting enzyme (ACE) gene and the endothelial nitric oxide synthase (eNOS) gene are associated with the development of systemic lupus erythematosus (SLE) and the progression of nephropathy. The aim of this study was to evaluate the possible association between six SNPs (A-5466C, T-3892C, A-240T, C1237T, G2215A and A2350G) of the ACE gene and two SNPs (T-786C and G894T) of the eNOS gene with lupus nephropathy in a northern Chinese population.

METHODS

In this study, 225 patients with lupus nephropathy were compared to 232 healthy controls, matched by gender, age and ethnicity. Following the extraction of genomic DNA from the leukocytes in the peripheral blood, the genotypes of the eight selected SNPs were determined by the method of PCR-RFLP; the haplotypes were inferred using PHASE 2.1. The associations between the SNPs and the risk of lupus nephropathy were analyzed using Chi-square test and Logistic regression with SPSS13.0 software.

RESULTS

Statistically significant differences of the allele frequency distribution of three SNPs (A-5466C, A2350G and G894T) were observed between cases and controls (P<0.05). Among the 53 haplotypes identified, the frequencies of five haplotypes (CTTCGA, ACTTAA, ACATGG, ACACGG and ATTCGA) were significantly different between cases and controls (P<0.05).

CONCLUSIONS

Our study indicated an association between the risk of lupus nephropathy and the sequence variations of both the ACE gene and the eNOS gene, which may play an important role in the pathogenesis of lupus nephropathy in the northern Chinese population. Further studies are warranted to validate our findings.