Biomass viability: An experimental study and the development of an empirical mathematical model for submerged membrane bioreactor

This study investigates the influence of key biomass parameters on specific oxygen uptake rate (SOUR) in a sponge submerged membrane bioreactor (SSMBR) to develop mathematical models of biomass viability. Extra-cellular polymeric substances (EPS) were considered as a lumped parameter of bound EPS (bEPS) and soluble microbial products (SMP). Statistical analyses of experimental results indicate that the bEPS, SMP, mixed liquor suspended solids and volatile suspended solids (MLSS and MLVSS) have functional relationships with SOUR and their relative influence on SOUR was in the order of EPS>bEPS>SMP>MLVSS/MLSS. Based on correlations among biomass parameters and SOUR, two independent empirical models of biomass viability were developed. The models were validated using results of the SSMBR. However, further validation of the models for different operating conditions is suggested.

CCL3 serves as a potential plasma biomarker in knee degeneration (osteoarthritis)

OBJECTIVE

To explore the ability of chemokines in plasma to detect the presence of pre-X-rays defined knee degeneration and the extent (burden).

METHODS

A total of 181 subjects (75 control subjects, 47 pre-X-KD patients and 50 X-KOA patients) were included and subdivided into three subgroups. Articular cartilage loss in pre-X-KD patients were scored on the basis of the ICRS classification during the arthroscopy or documented on MRI with chondral WORMS. The severity of X-KOA was graded using the Kellgren-Lawrence classification through the posterior-anterior knee X-rays. The concentrations of the inflammatory cytokines and chemokines in plasma were quantified using Luminex microbead-based suspension array (SA) and were cross-validated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

CCL3 in plasma showed the highest ability to discriminate pre-X-KD patients from the controls with an AUC of 0.799. At a cutoff value of 0.168 pg/ml, the sensitivity was 70.21%, the specificity was 96.00%, the positive predictive value was 91.67% and the negative predictive value was 83.72%. As to define disease burden, the plasma levels of resistin, IL6, IL8, CCL3 and CCL4 showed significant association with the severity of X-rays defined knee OA, with regard to the KL classification. Moreover, significant elevation of IL6, IL8, CCL3 and CCL4 levels in plasma were observed in severe knee OA patients (KL grade IV) compared with those with pre-X-KD (KL grade 0-I).

CONCLUSION

We firstly showed that the plasma CCL3 could be potential serum biomarker for knee OA with the capacity to detect pre-X-rays defined changes and stage the severity of damage in knee.

ROS-p53-cyclophilin-D signaling mediates salinomycin-induced glioma cell necrosis

BACKGROUND

The primary glioblastoma multiforme (GBM) is the most malignant form of astrocytic tumor with an average survival of approximately 12-14 months. The search for novel and more efficient chemo-agents against this disease is urgent. Salinomycin induces broad anti-cancer effects; however, its role in GBM and the underlying mechanism are not clear.

RESULTS

Here we found that salinomycin induced both apoptosis and necrosis in cultured glioma cells, and necrosis played a major role in contributing salinomycin's cytotoxicity. Salinomycin induced p53 translocation to mitochondria, where it formed a complex with cyclophilin-D (CyPD). This complexation was required for mitochondrial permeability transition pore (mPTP) opening and subsequent programmed necrosis. Blockade of Cyp-D by siRNA-mediated depletion or pharmacological inhibitors (cyclosporin A and sanglifehrin A) significantly suppressed salinomycin-induced glioma cell necrosis. Meanwhile, p53 stable knockdown alleviated salinomycin-induced necrosis in glioma cells. Reactive oxygen species (ROS) production was required for salinomycin-induced p53 mitochondrial translocation, mPTP opening and necrosis, and anti-oxidants n-acetylcysteine (NAC) and pyrrolidine dithiocarbamate (PDTC) inhibited p53 translocation, mPTP opening and glioma cell death.

CONCLUSIONS

Thus, salinomycin mainly induces programmed necrosis in cultured glioma cells.

[Protective effects of histone deacetylase inhibitor on stress-induced myocardial injury in rats]

OBJECTIVE

To observe the protective effects of histone deacetylase inhibitor on stress-induced myocardial injury.

METHODS

Healthy male Wistar rats were randomly divided into 3 groups( n = 6), and the stress-induced myocardial injury model was established with chronic restraint stress method. The protective effects of histone deacetylase inhibitor on stress-induced myocardial injury were observed with Trichostatin A (TSA) intervention. Histone acetylation levels in myocardium of rats were detected by Western blot method, spectrophotometry method was used to dynamically determine the activity of rat serum lactate dehydrogenase (LDH), serum creatine kinase isoenzyme-MB (CK-MB) and Caspase 3, and nagar Olsen staining were used to observe the early myocardial damage.

RESULTS

Restraint stress could significantly reduce the level of histone acetylation of myocardium in rats, and TSA intervention could inhibit the stress-induced reduction of myocardial levels of histone acetylation. Restraint stress could cause the significant increase of serum LDH activity ( P < 0.05), serum CK-MB activity ( P < 0.05), and the Caspase 3 activity of myocardial tissue (P < 0.05), and early myocardial damage also occurred during restraint stress. ISA intervention could significantly reduce the serum LDH activity (P < 0.05), the serum CK-MB activity (P < 0.05), the activity of myocardial tissue caspase 3 induced by restraint stress (P < 0.05), and the stress-induced myocardial injury was also attenuated by TSA intervention.

CONCLUSION

The histone deacetylase inhibitor TSA can protect stress-induced myocardial injury.

Downregulated miR-29c correlates with increased BACE1 expression in sporadic Alzheimer's disease

BACKGROUND

Beta-site Amyloid precursor protein Cleaving Enzyme 1 (BACE1) is conceived as a potential target for therapies against Alzheimer disease (AD) which is characterized by the accumulation of plaques formed of short β-amyloid (APPβ) peptides. Recently, such microRNAs, as miR-29a, miR-29b-1 have been shown to correlate with abnormally high levels of BACE1 and APPβ in sporadic AD.

METHODS

In order to confirm whether miR-29c correlates with the BACE1 upregulation in sporadic AD, we firstly evaluated the expression of miR-29c and BACE1, the APPβ accumulation in sporadic AD brain tissues and analyzed the correlation of miR-29c with BACE1. Then we determined the regulation of miR-29c in human heuroblastoma SH-SY5Y cells on the BACE1 expression and APPβ accumulation. And finally we determined the targeting to 3' UTR of BACE1 by miR-29c by a luciferase reporter.

RESULTS

It was demonstrated that miR-29c was downregulated in sporadic AD brains, in an association with an upregulation of BACE1 in both mRNA and protein level of BACE1, and also an elevated APPβ accumulation. And the manipulated high level of miR-29c with miR-29c mimics transfection significantly reduced the protein level of BACE1 and APPβ accumulation in human neuroblastoma SH-SY5Y cells. Further luciferase reporter assay demonstrated that miR-29c targets the 3' UTR of BACE1 and downregulated the BACE1 in HEK293 cells.

CONCLUSION

Present study indicated that miR-29c was downregulated in sporadic AD brains, and it targeted the 3' UTR of BACE1, reduced the BACE1 expression, and downregulated the APPβ accumulation in vitro.

Docetaxel-loaded PEO–PPO–PCL/TPGS mixed micelles for overcoming multidrug resistance and enhancing antitumor efficacy

A schematic diagram of DTX-loaded PEO–PPO–PCL/TPGS mixed micelles in vivo for overcoming multidrug resistance and enhancing antitumor efficacy.

[Phase transition behavior and thermodynamic analysis of hydrotalcite flame-retardant]

The hydrotalcite with the properties of flame-retardant, eliminating smoke, filling and thermostability is a new kind of inorganic flame retardant. In the work, the MgAl hydrotalcite as flame retardant with Mg/Al molar ratio of 4 (MgAl-LDH) was prepared by using urea as the precipitating agent. The thermolysis behavior of the MgAl-LDH flame retardant was investigated by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and thermogravimetry-differential scanning calorimetry (TG-DSC) as well as self deconvolution and curve-fitting analyses. Thermal phase transition of the MgAl-LDH was clarified, especially the characteristics of the hydroxyl groups (-OH) in the brucite-like layers and the changes in coordinate of the carbonate (CO3(2-)) from the interlayers. Based on thermodynamic data, thermal decomposition process was discussed. By.XRD analysis; it was found that the phase change took place when the decomposition temperature increased. The MgAl-LDH was decarbonated basically to MgAl mixed metal oxides (Mg-Al-O) at 500 °C, and impurity MgAl204 phase formed at 600 °C. According to the analyses of FT-IR, TG-DSC and curve-fitting technique, the hydroxyl groups (-OH) in the brucite-like layers possessed three the ligands such as [Al-OH-Al], [Al-OH-Mg] and [Mg-OH-Mg] modes. Dehydroxylation of the brucite-like layers based on the binding forces, where the [Mg-OH-Mg] among the three modes was the most difficult to be re- moved during the pyrolysis process. In the same way, the CO3(2-) ligands also possessed three modes such as H2O-bridged CO3(2-), monodentate and bidentate coordination modes. Based on the thermodynamic analysis, the thermodynamic properties of the hydrotalcite as flame retardant were evaluated, and the expressions of the Gibbs free energy, (ΔrGθT), as a function of temperature, were derived for the Mg8Al2 (OH)20CO3 crystal. Thermodynamic analysis showed that the removal of -OH from the brucite-like layers was spontaneous process, when the Gibbs free energy (ΔrGθT) was under zero at the temperature (T) above 228. 65 °C. The result and datum were close to the experimental result from the TG-DSC analyses, indicating that the relationship between the Gibbs free energy (ΔrGθT) and temperature (T) from thermodynamic analysis was reliable.

Additional waves in the graphene layered medium

We investigate the features of additional waves that arise in the graphene layered medium, within the framework of nonlocal effective medium model. The additional wave is manifest on the biquadratic dispersion relation of the medium and represents as a distinctive nonlocal character at long wavelength. In particular, the reflection and transmission coefficients for the nonlocal medium are underdetermined by Maxwell's boundary conditions. An additional boundary condition based on modal expansions is proposed to derive the generalized Fresnel equations, based on which the additional wave in the graphene layered medium is determined. The additional wave tends to be significant near the effective plasma frequency, near which the graphene plasmons are excited inside the medium.

Clinical image and pathology of hypertrophic cranial pachymeningitis

The objective of this study was to examine the clinical findings, magnetic resonance imaging (MRI), pathological features, and treatment experiments of patients with hypertrophic cranial pachymeningitis (HCP). The clinical findings, MRI, and pathological appearances of 9 patients with HCP were analyzed retrospectively. The thickened dura mater was markedly enhanced after contrast media injection. The lesion near the brain hemisphere presented long regions of T1- and T2-weighted abnormal signal intensities. The abnormal signal intensities of the brain tissue were decreased significantly. Pathological examination demonstrated chronic inflammation changes, with cerebral dura mater fibrous tissue showing obvious hyperplasia, and the periphery of the blood vessel showing a great quantity of infiltrating phlegmonosis cells. HCP mainly presents headache and paralysis of multiple cranial nerves. The distinctive signs on brain MRIs involve strengthening the signal in the cerebral dura.

Effects of hypoxia on proliferation and osteogenic differentiation of periodontal ligament stem cells: an in vitro and in vivo study

Changes in oxygen concentration may influence various innate characteristics of stem cells. The effects of varying oxygen concentration on human periodontal ligament stem cells (HPDLSCs) has not been explored, particularly under hypoxia-related conditions. First, HPDLSCs were cultured from the periodontium of human teeth using the outgrowth method. STRO-1 and CD146 expression of HPDLSCs was investigated by flow cytometry. To detect the multilineage differentiation capacities of HPDLSCs, osteogenic-like and adipogenic-like states were induced in cells. Next, HPDLSCs (passage 3) were exposed to normal oxygen (21% O2) or hypoxia (2% O2) conditions for 7 days and cell proliferation was evaluated. After culture in osteogenic medium for 7 days, osteoblastic differentiation was evaluated by semi-quantitative reverse transcription-polymerase chain reaction analysis to detect 3 osteoblastic markers: core-binding factor a 1/runt-related transcription factor 2, osteocalcin, and osteopontin. In addition, each cell group was incubated with a hydroxyapatite/tricalcium phosphate carrier and transplanted subcutaneously into the back of immunocompromised mice to investigate transplantation differences in vivo. HPDLSCs were isolated, cultured, and successfully identified. After exposure of HPDLSCs to hypoxia for 7 days, the proliferation rate was increased and showed higher osteogenic differentiation potential compared to control cells. After 12 weeks of transplantation, hypoxia-treated HPDLSCs differentiated into osteoblast-like cells that formed bone-like structures. These results suggest that oxygen concentrations affect various aspects of HPDLSC physiology and that hypoxia enhances osteogenic differentiation both in vivo and in vitro. Oxygen concentration may be a critical parameter for HPDLSCs during expansion and differentiation.

Functional expression, characterization and application of the human S100A4 protein

Preparations utilizing monoclonal antibodies against S100A4 provide useful tools for functional studies to investigate the clinical applications of the human S100A4 protein. In the present study, human S100A4 protein was expressed in Escherichia coli (E. coli) BL21 (DE3), successfully purified by diethylaminoethyl cellulose anion-exchange chromatography and identified by western blot analysis. Soluble S100A4 bioactivity was confirmed by Transwell migration and invasion assays in the human HeLa cell line. Monoclonal antibodies (mAbs) were generated utilizing the standard hybridoma method and were validated by enzyme-linked immunosorbent assay and western blot analysis. The antibody was then used to examine human gastric carcinoma specimens by immunohistochemistry. Recombinant S100A4 was functionally expressed in E. coli and promoted the migration and invasion of HeLa cells. Four hybridoma cell lines, which secreted mAbs specifically against human S100A4 protein, were obtained. One of the four mAbs, namely 2A12D10B2, recognized human S100A4 as indicated by immunohistochemical staining of human gastric carcinoma specimens and recombinant S100A4 was functionally expressed in E. coli. The mAbs of recombinant S100A4 were suitable for detecting S100A4 expression in human tissues and for investigating the subsequent clinical applications of the protein.

[Effects of non-physical factors on neck and shoulder pain and low back pain of adolescents]

OBJECTIVE

To explore the incidence of self-reported neck/shoulder pain (NSP) and lower back pain (LBP) among Chinese adolescents in Shanghai and identify the influencing factors for the incidences of these musculoskeletal disorders.

METHODS

A total of 3 600 students were selected from 30 high schools randomly chosen from 237 regular full-time high schools registered in Shanghai. From each school, 40 students were selected from each of the tenth, eleventh and twelfth grades for a total of 120 students per school. The questionnaire involved questions pertaining to demographic information, learning environment and exercise habits of each student. The questionnaire also contained questions regarding the amount of weight carried by each student while commuting to and from school. And it was also used to collect specific information related with the occurrence of NSP and LBP. Logistic regression was performed to analyze the potential risk factors for NSP and LBP.

RESULTS

Among 3 600 distributed questionnaires, a total of 2 842 valid questionnaires were returned. The results revealed that the incidences of NSP and LBP in the Chinese adolescent population were 41.1% and 32.8%, respectively. Both NSP and LBP were more common in girls than in boys. And 6.3% students reported at least one NSP- or LBP-induced absence from school. Chinese adolescents generally experienced a heavy academic burden (32.7% failing to achieve daily academic goals) and mental stress (16.3% suffering from insomnia); the problem of insufficient sleep was even more pronounced (52.0% falling asleep after midnight and 64.3% suffering insufficient sleep while only 31.9% feeling physically relaxed after awaking). The multivariate Logistic regression analysis suggested that gender, grade, academic burden, stress and sleep situation had a significant correlation with NSP and LBP in adolescents.

CONCLUSION

The incidences of NSP and LBP are relatively high among adolescents in Shanghai. And several factors, including sedentary behaviors, personal exercise habits and backpack weight, influences the occurrences of NSP and LBP in youth.

Decreased retinol-binding protein 4 in the sera of patients with end-stage renal disease after kidney transplantation

Retinol-binding protein 4 (RBP4) is a novel adipokine that has been associated with insulin resistance and type 2 diabetes. Patients with end-stage renal disease (ESRD) have very high serum RBP4 levels. However, whether successful kidney transplantation alleviates these elevated serum RBP4 levels is unclear. The serum RBP4 levels of 24 ESRD patients were determined before transplantation and at 1 day, 1 week, and 1 month after kidney transplantation. The control group included 22 healthy subjects. Serum RBP4 concentrations were measured using a commercial kit via the immunologic turbidimetric method, and were related to biomarkers for renal and liver function. The serum RBP4 level of ESRD patients before kidney transplantation (160.8 ± 29.1 mg/L) was approximately 7-fold higher than that of normal controls (22.6 ± 11.0 mg/L; P = 0.000). The serum RBP4 level before transplantation was significantly higher than that at 1 day (65.3 ± 28.4 mg/L), 1 week (48.3 ± 22.9 mg/L), and 1 month after transplantation (53.1 ± 25.5 mg/L; P = 0.000). However, these values were still higher than those of controls (P = 0.000). Univariate regression analysis showed that the percent changes in serum RBP4 concentration before and after kidney transplantation were positively correlated with serum creatinine, blood urea nitrogen, phosphate, and pre-albumin concentrations and negatively correlated with the estimated glomerular filtration rate. The serum RBP4 concentration of patients with ESRD decreased significantly after kidney transplantation; therefore, we found that serum RBP4 concentration was related to renal function.

A compact two-way high-power microwave combiner

A compact 2-way high-power microwave (HPM) waveguide combiner as an important equipment to realize the coherent microwave combination was theoretically designed, built, and proof-of-principle experimentally tested. The theoretical and experimental S-parameters are basically consistent with each other: return loss <-25 dB, and the isolation degree between 2-channels of the HPM combiner >25 dB to avoid the inter-modulating between the HPM sources. The C-band HPM experiment was carried out, and the power capacity of the HPM combiner was demonstrated to reach multi-gigawatts.

Functionally active rat S100A4 from a polymerase chain reaction-synthesized gene expressed in soluble form in Escherichia coli

S100A4 protein is associated with Ca²⁺-dependent regulation of intracellular activities and is significant in the invasion, growth and metastasis of cancer. In order to express rat S100A4 functionally and identify its biological activity following purification, an S100A4 gene fragment was optimized and fully synthesized via overlapping polymerase chain reaction. The gene was inserted into the prokaryotic expression vector, pBV220, with phage λ P_RP_L promoters following confirmation by DNA sequencing. The pBV220-S100A4 plasmid was constructed and transformed into Escherichia coli DH5α. Following temperature induction, rat S100A4 was overexpressed and the protein was observed to be located in the supernatant of the lysates, which was ~30–40% of the total protein within the host. The protein was isolated and purified by metal-chelate affinity chromatography. High purity protein (>98% purity) was obtained and in vitro western blot analysis identified that the recombinant S100A4 was able to bind to the antibody against wild-type S100A4. The bioactivity of the recombinant protein was detected via Transwell migration and invasion assays. The polyclonal antibody of rat S100A4 protein was prepared for rabbit immunization and exhibited similar efficacies when compared with commercial S100A4. Therefore, rat S100A4 was functionally expressed in E. coli; thus, the production of active recombinant S100A4 protein in E. coli may further aid with the investigation and application of S100A4.

Osteopontin (OPN) is an important protein to mediate improvements in the biocompatibility of C ion-implanted silicone rubber

Medical device implants are drawing increasing amounts of interest from modern medical practitioners. However, this attention is not evenly spread across all such devices; most of these implantable devices can cause adverse reactions such as inflammation, fibrosis, thrombosis, and infection. In this work, the biocompatibility of silicone rubber (SR) was improved through carbon (C) ion implantation. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results confirmed that these newly generated carbon-implanted silicone rubbers (C-SRs) had large, irregular peaks and deep valleys on their surfaces. The water contact angle of the SR surface decreased significantly after C ion implantation. C ion implantation also changed the surface charge distribution, silicone oxygen rate, and chemical-element distribution of SR to favor cell attachment. The dermal fibroblasts cultured on the surface C-SR grew faster and showed more typical fibroblastic shapes. The expression levels of major adhesion proteins, including talin-1, zyxin, and vinculin, were significantly higher in dermal fibroblasts cultured on C-SR coated plates than in dermal fibroblasts cultured on SR. Those same dermal fibroblasts on C-SRs showed more pronounced adhesion and migration abilities. Osteopontin (OPN), a critical extracellular matrix (ECM) protein, was up-regulated and secreted from dermal fibroblasts cultured on C-SR. Matrix metalloproteinase-9 (MMP-9) activity was also increased. These cells were highly mobile and were able to adhere to surfaces, but these abilities were inhibited by the monoclonal antibody against OPN, or by shRNA-mediated MMP-9 knockdown. Together, these results suggest that C ion implantation significantly improves SR biocompatibility, and that OPN is important to promote cell adhesion to the C-SR surface.

Suberoylanilide hydroxamic acid, an inhibitor of histone deacetylase, suppresses vasculogenic mimicry and proliferation of highly aggressive pancreatic cancer PaTu8988 cells

BACKGROUND

Pancreatic cancer is one of the most aggressive human malignancies with a extremely low 5-year survival rate. Hence, the search for more effective anti-pancreatic cancer agents is urgent.

METHODS

PaTu8988 pancreatic cancer cells were treated with different concentrations of suberoylanilide hydroxamic acid (SAHA), cell survival, proliferation, migration and vasculogenic mimicry (VM) were analyzed. Associated signaling changes were also analyzed by RT-PCR and Western blots.

RESULTS

Here, we reported that SAHA, a histone deacetylase inhibitor (HDACi), exerted significant inhibitory efficiency against pancreatic cancer cell survival, proliferation, migration and VM. SAHA dose-dependently inhibited PaTu8988 pancreatic cancer cell growth with the IC-50 of 3.4 ± 0. 7 μM. Meanwhile, SAHA suppressed PaTu8988 cell cycle progression through inducing G2/M arrest, which was associated with cyclin-dependent kinase 1 (CDK-1)/cyclin-B1 degradation and p21/p27 upregulation. Further, SAHA induced both apoptotic and non-apoptotic death of PaTu8988 cells. Significantly, SAHA suppressed PaTu8988 cell in vitro migration and cell-dominant tube formation or VM, which was accompanied by semaphorin-4D (Sema-4D) and integrin-β5 down-regulation. Our evidences showed that Akt activation might be important for Sema-4D expression in PaTu8988 cells, and SAHA-induced Sema-4D down-regulation might be associated with Akt inhibition.

CONCLUSIONS

This study is among the first to report the VM formation in cultured human pancreatic cancer cells. And we provided strong evidence to suggest that SAHA executes significant anti-VM efficiency in the progressive pancreatic cancer cells. Thus, SAHA could be further investigated as a promising anti-pancreatic cancer agent.

Decorin-induced proliferation of avian myoblasts involves the myostatin/Smad signaling pathway

Decorin, a small leucine-rich proteoglycan as a component of the extracellular matrix, plays an important role in the skeletal muscle development. It has been reported that decorin promoted proliferation and differentiation of muscle cells by restraining myostatin activity in rodents. However, the effects and mechanisms of decorin on avian myoblast proliferation are not understood clearly. Thus, in our research, decorin overexpressing and knocking-down quail myoblast-7 (QM7) myoblasts were established to explore the effects of decorin on avian myoblast proliferation by flow cytometry. The results showed that overexpression of decorin enhanced the proliferation of QM7 myoblasts, which was accompanied by the upregulation of follistatin and primary muscle regulatory factors (i.e., myogenic factor 5, myogenic factor 1, myogenin), and downregulation of myostatin expression, as well as the decreased phosphorylation level of SMAD family member 3 (Smad3). In line with expectations, decorin RNAi displayed an opposite effect on the proliferation and gene expression pattern of QM7 cells. In conclusion, our in vitro studies suggested the decorin-mediated myostatin/Smad signaling pathway might be involved in the regulation of avian myoblast proliferation.