The low expression of CD80 correlated with the vascular endothelial growth factor in esophageal cancer tissue

AIMS

To analyze the mRNA and protein expression of CD80 and vascular endothelial growth factor (VEGF) in esophageal cancer (EC) tissue, investigate the causes of esophageal cancer cell escape from immune surveillance.

METHODS

We detected the CD80 and VEGF mRNA with reverse transcription polymerase chain reaction (RT-PCR), CD80 protein with flow cytometry, VEGF protein with immunohistochemistry in the cancer tissues in 118 EC patients, and the normal esophageal tissue as controls.

RESULTS

The expression of CD80 mRNA and protein in cancer tissues were lower than that in the controls (p<0.01, respectively), The CD80 protein expression in poor differentiation was lower than that in the well and moderate (P<0.01), in the patients with lymph node metastasis lower than that with no metastasis (P=0.01), in stage IIIA patients lower than that in stages I and II patients (P=0.04); the VEGF mRNA and protein expression were just right opposite. The mean survival time in the CD80 positive group was significantly longer than that in the negative (p=0.041); while in VEGF positive group was lower than that in the negative (p=0.046). The CD80 expression of mRNA and protein were correlated negatively with VEGF in the cancer tissues (r=-0.82, -0.87, respectively).

CONCLUSION

It is suggested that CD80 was impaired in the EC tissues and correlated with the clinicopathological characteristics and prognosis, which indicated the dysfunction of immune system and enhancing the progression of EC. The low expression of CD80 correlated with the overexpression of VEGF.

Giant panda habitat networks and conservation: is this species adequately protected?

Context. Giant pandas (Ailuropoda melanoleuca) are restricted to six mountain ranges at the edge of the Tibetan Plateau. One of these ranges, the Qinling Mountains, contains the highest density of giant pandas and is home to ~20% of those remaining in the wild. Commercial logging and other developments have resulted in habitat fragmentation, and an efficient and powerful conservation network is now needed for the species in this area. Aims. This study sought to assess giant panda habitat and estimate the carrying capacity of this reserve network. Our goal was to improve the function and carrying capacity of the reserve network and facilitate population growth and gene flow among subpopulations of giant pandas. Methods. We use habitat suitability models to assess the efficacy of conservation networks. With estimation of carrying capacity by home range, we can reveal issues facing reserves and populations of endangered species they contain. Here, we define key habitat, linkages, corridors and overall connectivity and then use habitat network modelling and spatial analyses to design a conservation landscape for giant pandas across their Qinling Mountains stronghold. Key results. We found that 91% of giant panda sightings were in suitable or marginally suitable habitat. The total area of giant panda habitat present in the Qinling Mountains is ~1600 km2 fragmented across four key habitat blocks by national roads or other human activity. The current nature reserve network encompasses 71% of available suitable habitat and 62% of available marginal habitat, meaning a significant proportion of panda habitat remains outside the current conservation network. We found that giant panda reserves across this region are not equal in their carrying capacity; some reserves contain an overabundance of giant pandas and the wellbeing of these populations are in doubt. Conclusions. Our results highlight the potential risk of high densities and bamboo flowering events to the safety of giant pandas. With poor population size and heavy isolation, small populations will not persist without translocation. Implication. Redrawing the reserve network to correct localised problems may improve the function of the giant panda protection system, build capacity in the reserve network, and decrease human–wildlife conflict. We propose a new reserve and adjustment of the borders and region for three reserves.

Improving the performance of membrane bioreactors by powdered activated carbon dosing with cost considerations

Effects of powdered activated carbon (PAC) dosing on the overall performance of membrane bioreactors (MBR) were investigated in two bench-scale submerged MBRs. Positive impacts of PAC dosing on membrane fouling and the removal of 17beta-estradiol (E2) and 17alpha-ethyinylestradiol (EE2) were demonstrated over a six-month stable operational period. PAC dosing in the MBR increased the removal rates of E2 and EE2 by 3.4% and 15.8%, respectively. The average soluble extracellular polymeric substances (EPS) and colloidal total organic carbon (TOC) concentrations in the PAC-MBR sludge was 60.1% and 61.8% lower than the control MBR sludge, respectively. Lower soluble EPS and colloidal TOC concentrations in the PAC-MBR sludge resulted in a slower rate of trans-membrane pressure (TMP) increase during MBRs operation, which could prolong the lifespan of membranes. Cost assessment showed that PAC dosing could reduce the operating cost for membrane cleaning and/or membrane replacement by about 25%. The operating cost for PAC dosing could be offset by the benefit from its reducing the cost for membrane maintenance.

Effects of powdered activated carbon dosing on sludge characteristics and estrogen removal in membrane bioreactors

Sludge characteristics associated with filterability as well as the removal of a natural estrogen 17beta-estradiol (E2) and a synthetic estrogen 17alpha-ethyinylestradiol (EE2) were investigated in submerged membrane bioreactors (MBR) with and without the addition of powdered activated carbon (PAC) under the same experimental conditions. Positive impacts of PAC dosing on membrane fouling and the removal of E2 and EE2 were demonstrated over a six months stable operational period. Experimental results showed that PAC dosing resulted in lower concentrations of soluble extracellular polymeric substances (EPS) and colloidal total organic carbon (TOC) in the PAC-MBR sludge. The average soluble EPS and colloidal TOC concentrations in the PAC-MBR sludge was 60.1% and 61.8% lower than the control MBR sludge, respectively. Regardless of PAC dosing, concentrations of colloidal TOC were strongly related to concentrations of soluble EPS and soluble carbohydrates in the sludge. In addition, the mean flocs size of the sludge with PAC dosing was shifted from 49.4 microm to 60.3 microm. PAC dosing in the MBR increased the removal rates of E2 and EE2 by 3.4% and 15.8%, respectively.

Solid and liquid spectroscopic analysis (SALSA)--a soft x-ray spectroscopy endstation with a novel flow-through liquid cell

We present a novel synchrotron endstation with a flow-through liquid cell designed to study the electronic structure of liquids using soft x-ray spectroscopies. In this cell, the liquid under study is separated from the vacuum by a thin window membrane, such that the sample liquid can be investigated at ambient pressure. The temperature of the probing volume can be varied in a broad range and with a fast temperature response. The optimized design of the cell significantly reduces the amount of required sample liquid and allows the use of different window membrane types necessary to cover a broad energy range. The liquid cell is integrated into the solid and liquid spectroscopic analysis (SALSA) endstation that includes a high-resolution, high-transmission x-ray spectrometer and a state-of-the-art electron analyzer. The modular design of SALSA also allows the measurement of solid-state samples. The capabilities of the liquid cell and the x-ray spectrometer are demonstrated using a resonant inelastic x-ray scattering map of a 25 wt % NaOD solution.

The association between intensive glycemic control and vascular complications in type 2 diabetes mellitus: a meta-analysis

BACKGROUND AND AIM

In patients with type 2 diabetes mellitus, the relationship between lowering glycated hemoglobin (HbA(1c)) and macrovascular complications is not clear and therefore lowering the level of HbA(1c) is controversial.

METHODS AND RESULTS

We searched for all randomized controlled trials comparing the effects of intensive and standard glycemic control on vascular events in patients with type 2 diabetes mellitus. The primary endpoint was combined macrovascular complications, including cardiac events, stroke and peripheral vascular disease. Fixed and random effect models were used to analyze the results. Eight studies were included according to selection criteria. The results showed no benefits of intensive glycemic control on macrovascular and microvascular complications (P>0.1), but a higher rate of severe hypoglycemia (P<0.00001) in the intensive control group when the target HbA(1c) level was <7.0%. When the target HbA(1c) level was lowered to 7.0-7.9%, intensive glycemic control showed benefits on the reduction of microvascular events (P<0.05) without increasing the risk of severe hypoglycemia (P=0.74), but no influence on macrovascular complications (P>0.1).

CONCLUSION

The results of this analysis suggest that a target HbA(1c) level of 7.0-7.9% may be a better glycemic control target than that of <7.0% in patients with established type 2 diabetes mellitus.

[Studies on performance standard for hemolytic toxins in harmful bloom algae]

OBJECTIVE

To explore a performance standard for hemolytic toxins in harmful bloom algae.

METHODS

Using Chattonella marina as hemolytic substances producing organism, methods and conditions were compared and optimized including cell breakage, distillation temperature, blood origin and storage of algal pellets in extraction and activity determination of hemolytic toxins.

RESULTS

The hemolytic activity of C. marina broken by supersonic method was 288.23 HU/L, higher than that by freezing--thawing method (94.89 HU/L), suggesting that supersonic method could be more optimal to break microalgal cells. When the supersonic treatment times were 5, 10, 20 and 30 min, the hemolytic activities were 80.57, 157.45, 288.23 and 279.17 HU/L, respectively, indicating that 20 min of supersonic treatment was suitable. When the distillation temperature were 40, 60 and 80 degrees C, the hemolytic activities were 288.23, 124.97 and 120.68 HU/L, respectively, meaning that high distillation temperature in extraction of hemolytic substances lowed the hemolytic activities of samples. Bloods from various animals such as human, fish, rat and rabbit exhibited different sensitivity to the hemolytic toxins, of which rabbit erythrocyte was the most sensitive. The hemolytic activities to human, fish, rat and rabbit were 244.98, 288.23, 266.35 and 195.47HU/L, respectively. The storage of algal pellets for 3 days at the temperature of 0 degrees C did not reveal a significant loss in hemolytic activity, while significant losses were observed at the temperature of 20 degrees C or -20 degrees C only after one day.

CONCLUSION

Supersonic method could be more optimal to break cell in comparison with freeze-thaw method. Optimal conditions for broken algal cells by supersonic method were 200 W for 20 min at the temperature of 4 degrees C. The distillation temperature in extraction of hemolytic substances should be maintained under the temperature of 40 degrees C. The rabbit erythrocyte could be the most optimal blood to detect hemolytic activity due to its high sensitivity. The algal pellets could be kept at the temperature of 0 degrees C for 3 days before determination of activity.

Counterregulation of beta(2)-adrenoceptor function in human mast cells by stem cell factor

BACKGROUND

Mast cells contribute to the pathophysiology of asthma with the sustained release of both preformed and newly generated mediators in response to allergens and other diverse stimuli. Stem cell factor (SCF) is the key human mast cell growth factor, but also primes mast cells for mediator release. SCF expression is markedly increased in asthmatic airways. Short-acting beta(2)-adrenoceptor drugs such as albuterol inhibit human lung mast cell (HLMC) degranulation in vitro in the absence of SCF, but their effect in the presence of SCF is not known.

OBJECTIVE

The aim of this study was to elucidate the effects of albuterol on HLMC function in the presence of SCF.

METHODS

Mediator release and K(Ca)3.1 ion channel activity were analyzed in purified HLMC. Intracellular signalling and beta(2)-adrenoceptor phosphorylation and internalization were analyzed in the HMC-1 human mast cell line.

RESULTS

beta(2)-Adrenoceptor agonist-dependent inhibition of K(Ca)3.1 ion channels and HLMC mediator release was markedly attenuated in the presence of SCF. Remarkably, albuterol actually potentiated IgE-induced histamine release in a dose-dependent manner when both SCF and IgE were present. These effects were related to the SCF-dependent phosphorylation of Tyr350 on the beta(2)-adrenoceptor with immediate uncoupling of the receptor followed by receptor internalization.

CONCLUSION

The potentially beneficial effects of beta(2)-adrenoceptor agonists in asthmatic airways may be blunted as a result of the high concentrations of SCF present.

Perlecan domain I-conjugated, hyaluronic acid-based hydrogel particles for enhanced chondrogenic differentiation via BMP-2 release

We have developed a biomimetic growth factor delivery system that effectively stimulates the chondrogenic differentiation of the cultured mesenchymal stem cells via the controlled presentation of bone morphogenetic protein-2 (BMP-2). Hyaluronic acid (HA)-based, microscopic hydrogel particles (HGPs) with inherent nanopores and defined functional groups were synthesized by an inverse emulsion polymerization technique. Recombinantly produced, heparan sulfate (HS)-bearing perlecan domain I (PlnDI) was covalently immobilized to HA HGPs (HGP-P(1)) via a flexible poly(ethylene glycol) (PEG) linker through the lysine amines in the core protein of PlnDI employing reductive amination. Compared to HGP without PlnDI, HGP-P(1) exhibited significantly (p<0.05) higher BMP-2 binding capacity and distinctly different BMP-2 release kinetics. Heparitinase treatment increased the amount of BMP-2 released from HGP-P(1), confirming the HS-dependent BMP-2 binding. While BMP-2 was released from HGPs with a distinct burst release followed by a minimal cumulative release, its release from HGP-P(1) exhibited a minimal burst release followed by linear release kinetics over 15 days. The bioactivity of the hydrogel particles was evaluated using micromass culture of multipotent mesenchymal stem cells (MSCs), and the chondrogenic differentiation was assessed by the production of glycosaminoglycan, aggrecan and collagen type II. Our results revealed that BMP-2 loaded HGP-P(1) stimulates more robust cartilage specific ECM production as compared to BMP-2 loaded HGP, due to the ability of HGP-P(1) to potentiate BMP-2 and modulate its release with a near zero-order release kinetics. The PlnDI-conjugated, HA HGPs provide an improved BMP-2 delivery system for stimulating chondrogenic differentiation in vitro, with potential therapeutic application for cartilage repair and regeneration.

Co-suppression of miR-221/222 cluster suppresses human glioma cell growth by targeting p27kip1 in vitro and in vivo

MicroRNAs are short regulatory RNAs that negatively modulate protein expression at a post-transcriptional level. Emerging evidence suggests that altered regulation of miRNA may be involved in the pathogenesis of several types of cancers. In the current study, an inverse relationship between the expression of miR-221/miR-222 and the cell cycle inhibitor p27Kip1 was identified in U251 glioma cells. Co-suppression of miR-221/222 directly resulted in the up-regulation of p27Kip1 in the tested cells, consequently, affects their growth potential by reducing a G1 to S shift in the cell cycle. Consistently, miR-221/222 knocked-down through antisense 2'-OME-oligonucleotides increased p27Kip1 in U251 glioma subcutaneous mice and strongly reduced tumor growth in vivo through up regulation of p27Kip1. Our results suggest that miR-221/222 is a regulator of the tumor suppressor gene p27Kip1, and co-suppression of miR-221/222 expression in advanced gliomas may inhibit glioma cell proliferation by a mechanism involving the up-regulation of p27Kip1 in vitro and in vivo.

Sustainable valorization of plastic wastes for energy with environmental safety via High-Temperature Pyrolysis (HTP) and High-Temperature Steam Gasification (HTSG)

In the present study the energetic valorization of electric cable shredder residues (mixed plastics) has been investigated. Thermochemical conversion by means of High-Temperature Steam Gasification (HTSG) and High-Temperature Pyrolysis (HTP) was studied. The effects of temperature and reaction time--process parameters--were investigated. Comparison of the results showed that HTSG seems a more suitable process in terms of produced syngas quality (64%, v/v and 13MJ/Nm(3)) than HTP because of higher H(2) yield and lower tar content.

CHARMM: the biomolecular simulation program

CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems, the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983.