Functional clustering in hippocampal cultures: relating network structure and dynamics

In this work we investigate the relationship between gross anatomic structural network properties, neuronal dynamics and the resultant functional structure in dissociated rat hippocampal cultures. Specifically, we studied cultures as they developed under two conditions: the first supporting glial cell growth (high glial group), and the second one inhibiting it (low glial group). We then compared structural network properties and the spatio-temporal activity patterns of the neurons. Differences in dynamics between the two groups could be linked to the impact of the glial network on the neuronal network as the cultures developed. We also implemented a recently developed algorithm called the functional clustering algorithm (FCA) to obtain the resulting functional network structure. We show that this new algorithm is useful for capturing changes in functional network structure as the networks evolve over time. The FCA detects changes in functional structure that are consistent with expected dynamical differences due to the impact of the glial network. Cultures in the high glial group show an increase in global synchronization as the cultures age, while those in the low glial group remain locally synchronized. We additionally use the FCA to quantify the amount of synchronization present in the cultures and show that the total level of synchronization in the high glial group is stronger than in the low glial group. These results indicate an interdependence between the glial and neuronal networks present in dissociated cultures.

Abstract 2909: ApoFLIP: A bioactive peptide that restarts the apoptotic machinery in cancer cells

The cellular factors inhibiting apoptosis are often employed by cancer cells to resist therapy. c-FLIP is an endogenous inhibitor of apoptosis upregulated in many drug resistant tumors. Herein, we show that a peptide derived from c-FLIP is a potent inducer of apoptosis in both in vitro and in vivo cancer models. Mechanistic studies suggest that the apoptogenic peptide of c-FLIP (ApoFLIP) removes the inhibition of pro-apoptotic signaling at the level of activated death receptors by competing c-FLIPL off receptor complexes and clearing the way for activation of the caspase cascade. At the same time, ApoFLIP impairs the pro-survival signaling along the PI3K/Akt pathway by blocking the interaction between the p85 subunit of PI3K and c-FLIPL. The selectivity and apoptogenic potency of ApoFLIP in killing cancer cells suggests that simultaneous targeting of two or more hallmark features of cancer may prove to be a winning therapeutic strategy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2909.

N-P transition sensing behaviors of ZnO nanotubes exposed to NO2 gas

Hydrothermally synthesized ZnO nanotube arrays were used to fabricate the gas sensor for detection of the toxic gas NO2. The ZnO nanotube gas sensor exhibited sensitive response to NO2 down to 500 ppb at low temperature 30 degrees C. Abnormal temperature-dependent and concentration-dependent N-P transition behaviors were observed. The excellent sensing ability of the sensor and their anomalous conductivity behaviors may be attributed to the unique surface conductivity related to the hollow nanostructure feature. These sensing behaviors may help to comprehensively understand the sensing mechanism of 1D ZnO nanostructures and improve the selectivity of the ZnO gas sensor.

Hirschsprung's disease management: from multi staged operation to single staged transanal pull-through

Hirschsprung's disease (HD) is a common congenital disease of colorectum. Although it was described more than one century ago, the effective treatment was established only half a century later. The initially treatment consisted of preoperative diverting colostomy, followed by definite pull-through and closure of colostomy on later date. A variety of procedures like Swenson, Duhamel, Rehbein and Soave were evolved with time. With the better understanding of pathogenesis and improvement on surgical technique, now the operation has become less extensive. In recent days, the classical 3 staged procedure is replaced by single staged procedure. All the procedure can be completed transanally. Since De la Torre in 1998, first reported total transanal endorectal pull-through, it became the most popular technique for the treatment of HD.

[Establishment of human embryonic stem cell line NJGLLhES1]

OBJECTIVE

To report the derivation and characterization of a new human embryonic stem cell (hESC) line NJGLLhES1.

METHODS

From the inner cell mass of frozen-thawed human embryos and with ICR mouse embryonic fibroblasts as the feeder layer, we established a new human embryonic stem cell line, which was named NJGLLhES1. We detected the karyotype of the cell line, determined the expressions of alkaline phosphatase, the specific cell surface antigens SSEA-3, SSEA-4, TRA-1-60, TRA-1-81 and the marker gene Oct-4, and examined the formation of embryoids and teratomas.

RESULTS

NJGLLhES1 was maintained for over 1 year in vitro, with the morphological characteristics of hESC, a normal karyotype, positive expressions of alkaline phosphatase and specific cell marker genes, and the potential of forming embryoids and teratomas.

CONCLUSION

A new human embryonic stem cell line NJGLLhES1 was successfully established, which remains karyotypically and phenotypically stable, undifferentiated and capable of self-renewal and pluripotential differentiation.

[Immunostimulatory and antitumor effect of Flt3L and CCL5 on DNA vaccine in DNA prime/protein boost strategy]

AIM

To investigate the immune enhancment and antitumor effect of the recombinant plasmids pFlt3L and pCCL5 in DNA prime/protein boost regimens.

METHODS

The mice were coimmunized with HBcAg DNA vaccine and the two cytokines DNA constructs by intramuscular injection for three times at an interval of 2 weeks. Then the mice were boosted with HBc particle proteins or DNA vaccines, respectively. The immune efficacy was evaluated by tumor growth curve. To further investigate the mechanism of inhibiting tumor growth, lymphocytes proliferation response and the number of IFN-gamma-producing cells in splenocytes were measured by MTT or flow cytometry, respectively. The levels of IL-2 and IL-4 in supernatant of spleno-lymphocyte cultures were measured by ELISA. The CTL activity of spleno-lymphocyte was detected with LDH release assay.

RESULTS

Compared with negative control, DDP/Adj group significantly inhibit tumor growth; splenocytes proliferation response and the numbers of IFN-gamma-producing cells in DDD/Adj group and DDP/Adj group were significantly higher (P<0.05 or P<0.01). The levels of IL-2 in supernatant of spleno-lymphocyte cultures in DDD/Adj group and DDP/Adj group were also markedly higher than that of negative control (P<0.05); but the levels of IL-4 were no differences in all groups (P>0.05). The CTL activities in group of DDS/Adj and DDD/Adj were stronger than that of other groups (P<0.01 or P<0.05). While, the CTL killing activity in DDS/Adj group was over that of DDD/Adj (P<0.01 or P<0.05).

CONCLUSION

The significant Th1 response and specific CTL against B16-HBc tumor cells are elicited by the combination of Flt3L and CCL5 in the DNA prime/protein boost strategy.

[Establishment of B16-HLA-MAGE-3 melanoma cell line coexpressing HLA-A 0201/K(b) and MAGE-3 and its role in tumor vaccine evaluation]

AIM

To establish a tumor model in HLA-A2.1 transgenic mice to examine the efficacy of MAGE-3 vaccine, a cell line coexpressing HLA-A 0201/K(b) and MAGE-3 is established.

METHODS

B16-HLA-MAGE-3 melanoma was obtained by means of cotransfection of HLA-A 0201/K(b) and MAGE-3 to B16 melanoma. RT-PCR, FCM analysis and Western blot were used to detect the mRNA or protein of HLA-A 0201/K(b) or MAGE-3 expression in B16-HLA-MAGE-3. The ability of MAGE-3 antigen to be processed and presented in the B16-HLA-MAGE-3 cell line were observed by CTL activity detection and tumor challenge test.

RESULTS

Transcription and protein expression of HLA-A 0201/H-2k(b) and MAGE-3 were demonstrated in B16-HLA-MAGE-3 cells. CTL activity of splenocytes in immunized mice against B16-HLA-MAGE-3 was detected and the growth of B16-HLA-MAGE-3 in immunized mice was also inhibited.

CONCLUSION

MAGE-3 antigen is able to be processed and presented efficiently by B16-HLA-MAGE-3 melanoma cells and this cell can be employed to test HLA-A2 restricted epitope immunogenicity in the A2-transgenic mice.

Fast switching electrochromic display using a viologen-modified ZnO nanowire array electrode

We report an electrochromic (EC) display using a viologen-modified ZnO nanowire array as the EC electrode. The ZnO nanowire array was grown directly on an indium tin oxide (ITO) glass by a low temperature aqueous thermal decomposition method and then modified with viologen molecules. The ZnO nanowire electrochromic device shows fast switching time (170 and 142 ms for coloration and bleaching respectively for a 1 cm (2) cell), high coloration efficiency (196 C (-1) cm (2)) and good stability. The improved performance of the ZnO nanowires EC device can be attributed to the large surface area and high crystalline and good electron transport properties of the ZnO nanowire array.

[Effects of salinity and Na+/K+ in percolating water from saline-alkali soil on the growth of Litopenaeus vannamei]

In order to develop shrimp farming with the percolating water from coastal saline-alkali soil, the effects of the salinity and Na+/K+ in this percolating water on the survival, growth, metabolism, and glutamic oxaloacetic transaminase (GOT), glutamicpyruvic transaminase (GPT) and Na+-K+-ATPase activities of Litopenaeus vannamei were investigated. The shrimps were cultured at the salinity 5, 10 and 15 and at the Na+/K+ ratios of 20, 40, 50, 60, 70 and 90 for 20 days. The results showed that the survival rate, growth rate, and enzyme activities of the shrimps were the highest at salinity 15, and the shrimps had higher survival rate, growth rate, and enzyme activities at the Na+/K+ ratios of 40 and 50, suggesting that after an appropriate preparation, the percolating water from coastal saline-alkali soil was available to culture the shrimps.

A ZnO nanorod inorganic/organic heterostructure light-emitting diode emitting at 342 nm

An inorganic/organic heterostructure light-emitting diode consisting of the hole-transporting layer N, N'-di(naphth-2-yl)- N, N'-diphenylbenzidine (NPB) and n-type ZnO nanorods fabricated by hydrothermal decomposition is reported. Poly(methyl methacrylate) was used to form a smooth surface on top of ZnO nanorod array with ZnO nanorod tops exposed for subsequent NPB deposition. An unusual ultraviolet emission at 342 nm was observed in the electroluminescence spectrum. Compared to band gap energy of ZnO (3.37 eV), the excitonic emission is blue-shifted and broadened. The mechanism of the blue shift is discussed in terms of the energy band diagram of the heterostructure.

Perfluorinated compounds in the Pearl River and Yangtze River of China

A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/l and <0.01-14 ng/l in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0-260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9-26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions.

Enhanced field emission from injector-like ZnO nanostructures with minimized screening effect

Injector-like zinc oxide (ZnO) nanostructures have been synthesized on Si substrate by the vapour phase transport method. Samples with different areal densities were obtained by controlling the temperature. The field emission properties of the injector-like ZnO nanostructures showed a clear dependence on the areal density of the nanostructures, which is due to the screening effect. The samples with a needle length of 850 nm and an areal density of 1 × 10(8) cm(-2) showed the lowest field emission turn-on field of 1.85 V µm(-1) at a current density of 10 µA cm(-2), and the current density reaches 1 mA cm(-2) at an applied field of 4.7 V µm(-1).

[Expression and clinical significance of Ephrin-A1 in primary hepatocellular carcinoma]

OBJECTIVE

To investigate the expression and clinical significance of Ephrin-A1 mRNA and protein expression level in hepatocellular carcinoma.

METHODS

Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry technique were used to detect the expression of the Ephrin-A1 mRNA and protein of 40 cases of hepatocellular carcinoma and their corresponding para-cancerous tissues and 10 cases of normal liver tissues. The relationships with its clinical pathology characters were analyzed.

RESULTS

The mRNA of Ephrin-A1 was expressed in all of the 40 cases of hepatocellular carcinoma and their corresponding para-cancerous tissues and 10 cases of normal liver tissues. Semiquantitative analysis showed that the mRNA expression level of Ephrin-A1 in hepatocellular carcinoma (0.5413 +/- 0.1527) was greater than that in corresponding para-cancerous tissues (0.3895 +/- 0.0549, P < 0.05) and normal liver tissues (0.3770 +/- 0.1055, P < 0.05); but between corresponding para-cancerous tissues (0.3895 +/- 0.0549) and normal liver tissues (0.3770 +/- 0.1055), the mRNA expression level had no significant difference (P > 0.05). The positive rates of Ephrin-A1 protein were 20% (2/10) in normal tissues, 35% (14/40) in para-cancerous tissues and 62% (25/40) in hepatocellular carcinoma tissues, respectively; the protein expression level of Ephrin-A1 was gradually rising (chi(2) = 14.762, P < 0.05). The overexpression of Ephrin-A1 protein was correlated with histological differentiation, tumor thrombi in portal vein and lymph node metastasis (P < 0.05).

CONCLUSIONS

The overexpression of Ephrin-A1 protein is correlated with histological differentiation, the lymph node metastasis and tumor thrombi in portal vein. It indicates that Ephrin-A1 may play an important role in the malignancy transformation, invasion progression and metastasis of hepatocellular carcinoma.

A quantitative evaluation of human coordination interfaces for computer assisted surgery

Computer assisted surgery (CAS) for tumor resection can assist the surgeon in locating the tumor margin accurately via some form of guidance method. A wide array of guidance methods can be considered, including model-based visual representations, symbolic graphical interfaces, and those based on other sensory cues such as sound. Given the variety of these guidance methods, it becomes increasingly important to test and analyze guidance methods for CAS in a quantitative and context-dependent manner to determine which is most suitable for a given surgical task. In this paper, we present a novel experimental methodology and analysis framework to test candidate guidance methods for CAS. Different viewpoints and stereographic, symbolic and auditory cues were tested in isolation or in combination in a set of virtual surgery experiments. A total of 28 participants were asked to circumscribe a virtual tumor with a magnetically tracked scalpel while measuring the surgical trajectory. This allowed measurement of surgical accuracy, speed, and the frequency with which the tumor margin was intersected, and enabled a quantitative comparison of guidance approaches. This study demonstrated that adding sound to pictorial guidance methods consistently improved accuracy, speed and margin intersection of the virtual surgery. However, the use of stereovision showed less benefit than expected. While guidance based on a combination of symbolic and pictorial cues enhanced accuracy, we found that speed could be substantially impaired. These studies demonstrate that optimal guidance combinations exist which would not be apparent by studying individual guidance methods in isolation. Our findings suggest that care is needed when using expensive and sometimes cumbersome virtual visualization technologies for CAS, and that simpler, non-stereo presentation may be sufficient for specific surgical tasks.

Suppressive effect of a novel water-soluble artemisinin derivative SM905 on T cell activation and proliferation in vitro and in vivo

Artemisinin and its derivatives exhibit potent immunosuppressive activity. The aim of this study was to investigate the suppressive effects of SM905, a new water-soluble artemisinin derivative, on T lymphocytes both in vitro and in vivo, and explore its potential mode of action. The results showed that SM905 had a high inhibitory activity in Concanavalin A (ConA)-induced splenocyte proliferation and mixed lymphocyte reaction, and a relatively low cytotoxicity in vitro. In ovalbumin-immunized mice, oral administration of SM905 dose-dependently suppressed T cell proliferative response to ovalbumin, and inhibited anti-ovalbumin interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) production by T cells. Further studies showed that SM905 inhibited TCR (T cell receptor)/CD3 plus CD28-mediated primary T cell proliferation and cytokine production (IL-2 and IFN-gamma), and exerted an inhibitory action on the phosphorylation of mitogen-activated protein (MAP) kinases including extracellular signal-regulated kinase (ERK), p38 and Jun N-terminal kinase (JNK), and the activation of Ras. The results of this study provided experimental evidence that the new artemisinin derivative SM905 had immunosuppressive effects both in vitro and in vivo. SM905 suppressed T cell activation, which was associated with the inhibition of MAP kinases and Ras activation. Our results suggested a potential of SM905 to be developed as a new type agent for treating T cell-mediated immune disorder.

Synthesis and immunosuppressive activity of new artemisinin derivatives. Part 2: 2-[12(beta or alpha)-dihydroartemisinoxymethyl(or 1'-ethyl)]phenoxyl propionic acids and esters

Another series of novel dihydroartemisinin derivatives were synthesized and assessed for their cytotoxicity of lymphocyte, inhibitory activity on mitogen-induced spleen lymphocyte proliferation in vitro. Some of the compounds exhibited inhibitory effects on ConA-induced T cell and LPS-induced B cell proliferation comparable to or more potent than parent artemisinin.

Characterization of HLA-B*5516, -B*1313, -B*9512, and -DRB1*1457 alleles identified in a southwest Chinese population

The human leukocyte antigen (HLA)-B*5516 allele differs from the B*5502 by a single 97 T --> C substitution (His to Tyr at position 33) in exon 2. The B*1313 allele results from 419 T --> A and 420 A --> C substitutions, encoding a Leu to Tyr substitution at 140 in exon 2 of the B*1301 allele. The B*9512 allele differs from B*1502 by a single 360 G --> C substitution (Gln to His at 120) in exon 3. The DRB1*1457 allele appears to be a hybrid molecule generated by recombination between the DRB1*13 and DRB1*14 alleles. The serological equivalents of these new alleles are HLA-B22, -B13, -B15, and DR13, respectively. Family studies detected two rare haplotypes: A*11, B*9512, DRB1*14 and A*24, B*52, Cw*07, DRB1*1457, DRB3*020201, DQB1*050301. The gene frequencies of these alleles in the Chinese population are less than 0.0001.

Multiwalled carbon nanotubes coated fibers for solid-phase microextraction of polybrominated diphenyl ethers in water and milk samples before gas chromatography with electron-capture detection

Determination of polybrominated diphenyl ethers (PBDEs) in environmental samples has raised great concerns due to the widespread use of PBDEs and their potential risk to humans. Solid-phase microextraction (SPME) is a fast, simple, cost-effective, and green sample preparation technique and is widely used for environmental analysis, but reports on the application of SPME for determination of PBDEs are very limited, and only a few publications dealing with commercial SPME fibers are available for extraction of PBDEs. Herein, we report a novel SPME method using multiwalled carbon nanotubes (MWCNTs) as the SPME fiber coating for gas chromatography with electron-capture detection (GC-ECD) of PBDEs in environmental samples. The MWCNTs coating gave much higher enhancement factors (616-1756) than poly (5% dibenzene-95% dimethylsiloxane) coating (139-384) and activated carbon coating (193-423). Thirty-minute extraction of 10 mL of sample solution using the MWCNTs coated fiber for GC-ECD determination yielded the limits of detection of 3.6-8.6 ng L(-1) and exhibited good linearity of the calibration functions (r(2)>0.995). The precision (RSD%, n=4) for peak area and retention time at the 500 ng L(-1) level was 6.9-8.8% and 0.6-0.9%, respectively. The developed method was successfully applied for the analysis of real samples including local river water, wastewater, and milk samples. The recovery of the PBDEs at 500 ng L(-1) spiked in these samples ranged from 90 to 119%. No PBDEs were detected in the river water and skimmed milk samples, whereas in the wastewater sample, 134-215 ng L(-1) of PBDEs were found. The PBDEs were detected in all whole fat milk samples, ranging from 13 to 484 ng L(-1). In a semiskimmed milk sample, only BDE-47 was found at 21 ng L(-1).

[Study on effects of anticancer and immunoregulation of Fuganchun 6 on hepatoma of mouse]

OBJECTIVE

To study the anticancerous effect of Fuganchun 6 (FGC-6) and its immunoregulatory effect on tumor-bearing mice.

METHOD

The mice inoculated by H22 cells were divided into 5 groups: model group, 5-Fu group and FGC-6 in high dose, medium dose, and low dose groups. The normal mice were also observed. These mice were treated for 10 days. The weight of tumor mass and mouse were examined. The target-cell-killing activity of NK cells. The proliferation activity of lymphocyte and the production of IL-2 of murine splenocytes were detected respectively. The serum containing FGC-6 was prepared and its inhibition effect on H22 cells was examined by MTT assay and growth curve in vitro.

RESULT

Growth of tumor was inhibited markedly by FGC-6 high dose. The inhibition of serum containing FGC-6 on the proliferation of H22 cells in vitro was observerd in a dose and time-dependent manner. The target-cell-killing activity of NK cells and the production of IL-2 of murine splenocytes of model group were lower than those of normal group (P < 0.05). When compared with model group, FGC-6 in high dose elevated the two indexes above-mentioned, and also enhanced the proliferation activity of lymphocyte markedly (P < 0.05). The production of IL-2 of murine splenocytes was also improved when treated by FGC-6 in medium dose (P < 0.05).

CONCLUSION

FGC-6 can inhibite the growth of H22 cells markedly and also can strengthen the immunity of H22 transplanted mouse.

Observation of two new N* peaks in J/psi-->ppi-n and ppi+n decays

The decay J/psi-->NNpi provides an effective isospin 1/2 filter for the piN system due to isospin conservation. Using 58x10(6) J/psi decays collected with the Beijing Electromagnetic Spectrometer at the Beijing Electron Positron Collider, more than 100 thousand J/psi-->ppi-n+c.c. events are obtained. Besides the two well-known N* peaks at around 1500 MeV/c2 and 1670 MeV/c2, there are two new, clear N* peaks in the ppi invariant mass spectrum around 1360 MeV/c2 and 2030 MeV/c2 with statistical significance of 11sigma and 13sigma, respectively. We identify these as the first direct observation of the N*(1440) peak and a long-sought missing N* peak above 2 GeV/c2 in the piN invariant mass spectrum.

[Preparing of Al2O3/ZrO2 composite dental ceramics through isostatic pressing technology]

OBJECTIVE

To find out how to prepare high-density dental ceramics through isostatic pressing so that sintering shrinkage will be reduced.

METHODS

To prepare Al2O3/ZrO2 composite powder first, then to mold through dry-pressing, and to shape the green-body through isostatic pressing. The green-bodies were sintered at the temperature of 1 400 degrees C and kept at the temperature for different period of time (2 h, 3 h, 4 h). After that, the density and fracture strength were measured and the microstructure observed by scanning electron microscope (SEM).

RESULTS

The sample product's density, line-shrinkage, and fracture strength of ceramics was rising with the sintering time lengthened. The sample product kept under the temperature of 1 400 degrees C for 4 hours, the fracture strength was (497.27 +/- 78.45) MPa and glass phase distributed evenly in the ceramics and the grains were integrated owing to the glass phase. The longer the sintering time, the more even the microstructure was.

CONCLUSION

The sintering quality and the efficiency were improved through isostatic pressing.