Tunability of mobility and conductivity over large ranges in poly(3,3'''-didodecylquaterthiophene)/insulating polymer composites

Semiconducting polymers are currently being considered as active layers in field-effect transistors, in which high charge carrier mobility and low off conductivity are important. For other applications, such as certain spintronic mechanisms, the opposite characteristics are desirable. Blending such polymers with insulating polymers would be expected to lower the mobility. In this paper, we report that the use of hydrocarbon polymers such as polystyrene as insulators generally raises the mobility when the semiconducting polymer is poly(bisdodecylquaterthiophene). A high mobility value of nearly 0.1 cm(2)/V.s was obtained for an optimal blend. While this is counterintuitive, it is consistent with a few other recent reports. In order to lower the mobility significantly, a much more polar and irregular blending agent is needed. The further addition of tetrafluorotetracyanoquinodimethane as a dopant gave a rare low mobility/high conductivity combination of properties, with a charge carrier density on the order of 10(19) cm(-3). Thus, mobility and conductivity were tuned somewhat independently over 3 and 4 orders of magnitude, respectively.

Hermodulins: bispecific ligand traps inhibit breast tumor growth and metastasis

Abstract #4127

Signalling by the human EGF (HER) receptor family can induce tumorigenicity and metastasis of cancer cells. Activation of these receptors has been associated with aggressive phenotypes and poor prognosis of breast cancer and other malignancies. Currently approved HER family targeted therapeutics are primarily directed against one member of the HER family.
 We have engineered a family of bispecific (HER1:HER3) heterodimers comprised of a human IgG1-Fc fragment fused with modified extracellular domains of HER1 and HER3. These compounds, termed Hermodulins, act as “ligand traps” and inhibit ligand-stimulated activity of all members of the HER family. In this study we have shown that Hermodulins can inhibit in vitro growth and motility in breast cancer cell lines, act synergistically with other HER-directed tyrosine kinase inhibitors and monoclonal antibody therapeutics in tumor cell antiproliferation assays, and decrease the formation of osteolytic bone metastases in animal models.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4127.

In vitro evaluation of nanosized carbonate-substituted hydroxyapatite and its polyhydroxyethylmethacrylate nanocomposite

Nanometer scale carbonate-substituted hydroxyapatite (nanoCHA) particles were prepared and examined using transmission electron microscopy, which revealed their polycrystalline nature with a rod-like morphology (20-30 nm in width and 50-80 nm in length). In vitro cytotoxicity study showed that there was some evidence of lactate dehydrogenase (LDH) release when macrophages were in contact with high concentrations of nanoCHA particles. The levels of LDH release decreased significantly with a reduction in nanoCHA concentration. A similar trend was observed for the inflammatory cytokine TNF-alpha. nanoCHA particles with high carbonate content induced a high level of TNF-alpha release. Biological testing using a human osteoblast (HOB) cell model found that HOB cells were able to grow and proliferate on a nanoCHA deposited surface. Well organized actin fibers were observed for HOB cells in contact with nanoCHA particles with low carbonate content and the cell proliferation rate was higher on these particles in comparison with those of high carbonate nanoCHA particles. Therefore, low carbonate nanoCHA particles were incorporated into poly-(2-hydroxyethylmethacrylate) matrix to make a nanocomposite. It was found that the nanoCHA composite was hydrophilic and became rubber-like after hydration. Both 20 wt % and 40 wt % composites were able to induce the formation of bone-like apatite after immersion in simulated body fluid. A high bioactivity of the composite was obtained with high loading of the nanoCHA filler. These results demonstrate the potential of formulating nanocomposites for biomedical applications.

Genome screen of late-onset Alzheimer's extended pedigrees identifies TRPC4AP by haplotype analysis

Alzheimer's disease is a complex progressive neurodegenerative disorder with profound cognitive decline. Multiple susceptibility genetic variants have been identified with equivocal replication. While rare, collections of extended pedigrees with multiple affected family members are invaluable for genome-wide screens. We have used two extended pedigrees, having 14-15 siblings with four to five affected late-onset Alzheimer's disease patients in each, to identify the gene, transient receptor potential cation channel, subfamily C, member 4 associated protein (TRPC4AP), on chromosome 20q11.22, as relevant for the disease. Multiple significant SNPs in this gene were found with the initial genome scan (after Bonferroni correction). Additional SNPs were assessed in the families and in the controls which were also significant by haplotype analysis. Moreover, 36% of the patients' haplotypes in our collection of late-onset patients had the same haplotype. These results suggest that TRPC4AP is involved with the disease in these late-onset Alzheimer's families. The results also confirm the use of the genome-wide association study for identifying new genetic variants of complex diseases.

An Outbreak of Head Rot of Cabbage Caused by Rhizoctonia solani AG2-1 in Central China

In July of 2007, an outbreak of head rot of cabbage (Brassica oleracea) occurred on more than 2,500 ha in Changyang County, Hubei Province, China. On average, yields were reduced by approximately 50%. Affected plants were first observed in 2006, and symptoms were considered physiological or nutritional disorders by growers. In 2007, the more extensive summer rains favored an increase in disease severity. Initial symptoms consisted of irregular, brown-to-black lesions on leaves and sometimes a wet decay of the base of outer leaves. Lesions expanded until entire heads were rotted. Rhizoctonia solani was recovered consistently from symptomatic plant tissues. Five isolates were used to evaluate cultural and morphological characteristics of the pathogen. On potato dextrose agar (PDA), all isolates yielded colonies that became brown after 5 days of incubation. The hyphae, 4.9 to 8.0 μm in diameter, branched at right or acute angles near the septa and each cell usually had six to eight nuclei. Dark brown sclerotia, 0.5 to 5 mm in diameter, appeared after 10 days of incubation. Genomic DNA of a representative isolate, CY-1, was extracted, and the rDNA-internal transcribed spacer sequence showed 99.5% identity to R. solani AG2-1 (Accession No. EU513147) in GenBank. Pathogenicity tests were completed in the laboratory by placing 6-mm-diameter mycelial plugs from 3-day-old PDA cultures of the five isolates onto 30 cabbage leaves detached from 5-week-old cabbage plants. The inoculated leaves were incubated at 28°C with 95% relative humidity in a controlled environment chamber. Two days after inoculation, black, wet lesions were observed on all inoculated leaves, while no symptoms were apparent on leaves inoculated with noncolonized PDA plugs. Koch's postulates were fulfilled by reisolating R. solani from diseased leaves. R. solani AG1 (1), AG2-1 (2), and AG4 (4) have been reported as causal agents of diseases of cabbage and related plants, and AG2-1 has been previously isolated from cabbage grown in southwest China (3), but to our knowledge, this is the most severe outbreak reported from China. References: (1) G. S. Abawi and S. B. Martin. Plant Dis. 69:158, 1985. (2) L. Corazza et al. Eur. J. Plant Pathol. 101:341, 1995. (3) H. R. Li and H. H. Zhu. J. Yunnan Agric. Univ. 3:247, 1993. (4) G. H. Yang et al. Plant Pathol. 56:351, 2007.

Health risk assessment of organic pollutants in Jiangsu reach of the Huaihe River, China

In order to evaluate the potential health risk to local public caused by water pollution in Jiangsu reach of the Huaihe River, various organic pollutants, including Polycyclic Aromatic Hydrocarbons (PAHs), Organochlorine Pesticides (OCPs) and some other Semi-Volatile Organic Compounds (SVOCs), were determined. Preliminary health risk assessment (HRA) was performed by calculating the probability that the concentrations of detected compounds exceeded HHCWO (Human Health Criteria for Consumption of Water and Organism) after Kolmogorov-Smirnov test. The probabilities of posing a risk higher than 10(-6) for most potential carcinogens were greater than 0.5, and some even approximated 1. Further HRA for potential carcinogens was performed based on Monte Carlo simulation. Cumulative Risk Probability (CRP) was introduced to characterize risk. The result showed that 3,3'-dichlorobenzidine posed the highest risk. PAHs with 4 approximately 6 rings and some OCPs, such as heptachlorepoxide, aldrin and o,p'-DDT, also posed relatively high risk. Generally, there was a high level of heath risk in the study area. The study validated the high cancer incidence rate in areas along the Huaihe River.

Regulation of apoptosis by type III interferons

OBJECTIVE

Two types of interferons (IFNs), type I (IFN-alpha/beta) and type III (IFN-lambdas), utilize distinct receptor complexes to induce similar signalling and biological activities, including recently demonstrated for IFN-lambdas antitumour activity. However, ability of type III IFNs to regulate cell population growth remains largely uncharacterized.

MATERIALS AND METHODS

Intact and modified human colorectal adenocarcinoma HT29 cells were used to study regulation of apoptosis by IFN-lambdas.

RESULTS AND CONCLUSIONS

We report that the IFN-lambdaR1 chain of the type III IFN receptor complex possesses an intrinsic ability to trigger apoptosis in cells. Signalling induced through the intracellular domain of IFN-lambdaR1 resulted in G(1)/G(0) phase cell cycle arrest, phosphatidylserine surfacing and chromosomal DNA fragmentation. Caspase-3, caspase-8 and caspase-9 were activated; however, pancaspase inhibitor Z-VAD-FMK did not prevent apoptosis. In addition, the extent of apoptosis correlated with the level of receptor expression and was associated with prolonged IFN-lambda signalling. We also demonstrated that the ability to trigger apoptosis is a unique intrinsic function of all IFN receptors. However, more robust apoptosis was induced by signalling through type III IFN receptor than through type I or type II (IFN-gamma) receptors, suggesting higher cytotoxic potential of type III IFNs. In addition, we observed that IFN-gamma treatment sensitized HT29 cells to IFN-lambda-mediated apoptosis. These results provide evidence that type III IFNs, alone or in combination with other stimuli, have the potential to induce apoptosis.

Effects of tea polyphenols on ovarian development in rats

Tea is the most consumed beverage in the world. Tea polyphenols are the major constituents of tea leaves and have shown many potential healthy benefits. However, whether tea polyphenols influence ovarian follicle assembly and development and ovarian life span is unknown. To study the effect of tea polyphenols on ovarian follicle development and oocyte apoptosis, we investigated rat ovarian development of different ages [from postnatal day (PD)1 after birth to 10 months] after treatment with tea polyphenols. Our data showed that the percentage of unassembled follicles increased in the ovaries of 1- and 2-day-old rats which were ip injected with tea polyphenols (50 mg/kg/d) or whose mothers were treated with tea polyphenols (100 mg/kg/d) by intragastric administration from the day 11 after the detection of vaginal plug till delivery. The percentage of primordial follicles increased, while that of developing follicles decreased in the ovaries of 4- and 8-day-old rats following peritoneal injection with tea polyphenols compared with controls. The ratio of terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL)-positive oocytes decreased in the ovaries of neonatal rats following tea polyphenol treatment. In the 3- and 10-month-old rat ovaries, the number of primordial follicles augmented, whereas that of atretic follicles decreased after the treatment for 4 weeks. These data suggest that tea polyphenols may inhibit the transition from primordial to developing follicles, extend the entire growth phase of a follicle, and reduce dominant follicle numbers per cycle to increase the reserve of germ cells, inhibit oocyte apoptosis and follicle atresia during ovarian development from birth to early aged, and retard climacterium in rats. Drinking even a small cup of tea per day may benefit to extent the productive life of ovary.

Automated diagnosis of fetal alcohol syndrome using 3D facial image analysis

OBJECTIVES

Use three-dimensional (3D) facial laser scanned images from children with fetal alcohol syndrome (FAS) and controls to develop an automated diagnosis technique that can reliably and accurately identify individuals prenatally exposed to alcohol.

METHODS

A detailed dysmorphology evaluation, history of prenatal alcohol exposure, and 3D facial laser scans were obtained from 149 individuals (86 FAS; 63 Control) recruited from two study sites (Cape Town, South Africa and Helsinki, Finland). Computer graphics, machine learning, and pattern recognition techniques were used to automatically identify a set of facial features that best discriminated individuals with FAS from controls in each sample.

RESULTS

An automated feature detection and analysis technique was developed and applied to the two study populations. A unique set of facial regions and features were identified for each population that accurately discriminated FAS and control faces without any human intervention.

CONCLUSION

Our results demonstrate that computer algorithms can be used to automatically detect facial features that can discriminate FAS and control faces.

Bone marrow-derived mesenchymal stem cells are capable of mediating hepatitis B virus infection in injured tissues

We have previously showed that endothelial progenitor cells (EPCs) through uptake of hepatitis B virus (HBV) may play a critical role in mediating extrahepatic HBV diseases. However, it remains to be elucidated whether mesenchymal stem cells (MSCs) are capable of mediating HBV trans-infection into extrahepatic tissues.

METHODS AND RESULTS

In this study, we showed that HBV antigens, HBV DNA and the viral particles were detected in MSCs after 3 days virus challenge. Neither HBV covalently closed circular DNA nor pregenomic RNA were detected in MSCs. Intravenously transplantation of HBV-exposed MSCs into myocardial infarction mouse model resulted in incorporation of HBV into injured heart and other damaged tissues.

CONCLUSION

These results indicate that MSCs could serve as an additional extrahepatic virus reservoir, which may play a role at least in part in mediating HBV trans-infection into the injured tissues through the process of MSCs recruitment.

Expression and distribution of S-100, CD83 and apoptosis-related proteins (Fas, FasL and Bcl-2) in tissues of thyroid carcinoma

Previous studies have shown that dendritic cells (DCs) and apoptosis play a critical role in the pathogenesis of thyroid carcinoma (TC). This study was designed to investigate the expression and distribution of S-100 protein, CD83 and apoptosis-related proteins (Fas, FasL and Bcl-2) in the thyroid tissues of thyroid papillary carcinoma (TPC) and their role in TPC pathogenesis. Immunohistochemical staining techniques and other methods were used on pathological tissues of 30 patients with Thyroid papillary carcinoma (TPC) and 30 cases of thyroid follicular adenoma (TFA,as control) to detect the expression and distribution of S-100 protein, CD83, Fas, FasL and Bcl-2. A higher expression of S-100 protein in TPC (4.6+/-3.2%) vs.TFA (0.95+/-0.64%) (p<0.001) was observed as well as a higher expression of CD83 in the peri-cancerous tissues (PCT) (32.51+/-22.32) vs. TFA (5.19+/-8.08) (p<0.001), oppositely, CD83 was negative in the cancerous net.TPC showed greater increases in levels of Fas, FasL and Bcl-2 than did the TFA. Our findings suggest that impaired immune function, absence of CD83-positive mature and activated dendritic cells in cancer nodules may have a role in the pathogenesis of thyroid papillary carcinoma.The regulation of Fas, FasL and Bcl-2 in TPC may help them evade the immune system.

Influence of nanohydroxyapatite patterns deposited by electrohydrodynamic spraying on osteoblast response

Electrohydrodynamic spraying has been used to produce patterns of line width up to 100 microm in size on glass discs, using nanohydroxyapatite (nHA). A human osteoblast (HOB)-like cell model was then used to study the interaction between the HOB cells and nHA patterns in vitro. Growth of the cells was significantly increased (p < 0.05) on the nHA surfaces. In addition, HOBs attached and spread well, secreting extracellular matrix. It was found that a confluent, aligned cell layer was achieved on nHA patterns by day 9. Immunofluorescent staining indicated that these cells showed elongated nuclei, enhanced adhesion (vinculin adhesion plaques) and a well-aligned cytoskeleton (actin stress fibres). This work suggests that this type of spraying may provide a route for the production of nanoscale features on implants for biomedical applications.

Error tolerant DNA self-assembly using (2k - 1)x(2k - 1) snake tile sets

DNA self-assembly has been advocated as a possible technique for bottom-up manufacturing of scaffolds for computing systems in the nanoscale region. However, self-assembly is affected by different types of errors (such as growth and facet roughening) that severely limit its applicability. Different methods for reducing the error rate of self-assembly using tiles as basic elements have been proposed. A particularly effective method relies on snake tile sets that utilize a square block of even size (i.e., 2k x 2k tiles, k = 2, 3, . . .). In this paper, an odd-sized square block [i.e., (2k - 1) x (2k - 1)] is proposed as basis for the snake tile set. Compared with other tile sets, the proposed snake tile sets achieve a considerable reduction in error rate at a very modest reduction in growth rate. Growth and facet roughening errors are considered and analytical results are presented to prove the reduction in error rate compared with an even-sized snake tile set. Simulation results are provided.