Interactions between endothelial cells and electrospun methacrylic terpolymer fibers for engineered vascular replacements

A compliant terpolymer made of hexylmethacrylate (HMA), methylmethacrylate (MMA), and methacrylic acid (MAA) intended for use in small diameter vascular graft applications has been developed. The mechanical properties and in vitro biostability of this terpolymer have been previously characterized. The goal of this investigation was to examine the interactions between endothelial cells and the new terpolymer and to evaluate endothelial cell function. Electrospinning was used to produce both oriented and random terpolymer fiber scaffolds. Smooth solution cast films and tissue culture polystyrene were used as negative and positive controls, respectively. Human blood outgrowth endothelial cells and human umbilical vein endothelial cells were incubated with the test and control samples and characterized with respect to initial cell attachment, proliferation, viability, and maintenance of the endothelial cell phenotype. It was found that the terpolymer is cytocompatible allowing endothelial cell growth, with random fibers being more effective in promoting enhanced cellular activities than oriented fibers. In addition, endothelial cells cultured on these substrates appeared to maintain their phenotype. The results from this study demonstrate that electrospun HMA:MMA:MAA terpolymer has the potential to be used successfully in fabricating small diameter blood vessel replacements.

New limits on the ultrahigh energy cosmic neutrino flux from the ANITA experiment

We report initial results of the first flight of the Antarctic Impulsive Transient Antenna (ANITA-1) 2006-2007 Long Duration Balloon flight, which searched for evidence of a diffuse flux of cosmic neutrinos above energies of E(nu) approximately 3 x 10(18) eV. ANITA-1 flew for 35 days looking for radio impulses due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. We report here on our initial analysis, which was performed as a blind search of the data. No neutrino candidates are seen, with no detected physics background. We set model-independent limits based on this result. Upper limits derived from our analysis rule out the highest cosmogenic neutrino models. In a background horizontal-polarization channel, we also detect six events consistent with radio impulses from ultrahigh energy extensive air showers.

Study of anxiety and depression in cervical cancer survivors

e20644

Background: Cervical cancer is the second leading cause of cancer related deaths among women in Korea. However, few studies have been conducted to elucidate the psychological distress of this population. This study aimed to examine the prevalence of anxiety and depression among cervical cancer survivors, and to identify factors associated with such caseness. Methods: A total of 832 cervical cancer survivors recruited from six large hospitals in Korea completed a mailed survey, which included the Hospital Anxiety and Depression Scale (HADS), European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, and QLQ-CX24. Anxiety and depression were defined by a score of ≥ 8 on the HADS subscales. With a framework that included socio-demographic, clinical, and symptom characteristics, multivariate logistic regression models were used to identify factors associated with anxiety and depression. Results: Among cervical cancer survivors, 34.3% reported HADS-defined anxiety and 39.7% reported HADS-defined depression. Anxiety was associated with having a lower income (OR=1.95, p=.021), smoking (OR=2.42, p=.002), poor body image (OR=3.26, p<.001), peripheral neuropathy (OR=2.21, p=.002), menopausal symptoms (OR=2.02, p=.004), and sexual inactivity (OR=2.35, p=.001). Depression was associated with younger age (OR=1.75, p=.006), having a lower income (OR=2.14 p<.001), drinking (OR=1.56, p=.050), poor body image (OR=4.59, p<.001), peripheral neuropathy (OR=2.34, p<.001), and sexual inactivity (OR=2.68, p=.002). Both anxiety and depression were influenced by socio-demographic factors, health behaviors, and cervical cancer-specific symptom characteristics rather than cancer- or treatment-related factors. Conclusions: Anxiety and depression were highly prevalent among cervical cancer survivors in Korea. This examination of risk factors for anxiety and depression will be helpful for the development of clinical management strategies in cervical cancer survivors.

No significant financial relationships to disclose.

a5b1 integrin mediates survival of breast cancer cells in 3-dimensional culture that can be specifically targeted for therapy

Abstract #4126

Background: β1 integrin signaling has been implicated in breast cancer progression and has been shown to facilitate resistance to radiation that could be abrogated using β1 integrin inhibitory antibody, AIIB2. In the present study, we investigated whether a specific alpha heterodimer of β1 integrin was preferentially mediating a pro-survival signal in human breast cancer cells, and if it could specifically be targeted for therapy.&#x2028; Materials and Methods: We used three-dimensional (3D) laminin-rich extracellular matrix (lrECM) culture to compare the relative levels of alpha heterodimer expression in malignant HMT3522-T4-2 and nonmalignant cell line HMT3522-S-1. Total cell lysates were probed by western blot to detect several possible alpha integrins. In addition, to investigate whether α5β1 mediated an important pro-survival signal, we treated 3D lrECM cultures with a small peptide inhibitor of α5β1 integrin and fibronectin interaction, Ac-PHSCN-NH2 (ATN-161) and measured apoptotic response using TUNEL (terminal deoxynucleotidyl transferase (TdT)-mediated nick end labeling) assay.&#x2028; Results: We found that expression of α5β1 was upregulated in HMT3522-T4-2 malignant breast cell line compared to nonmalignant cell line HMT3522-S-1. Inhibition using ATN-161 resulted in a significant dose-dependent increase in TUNEL positive cells.&#x2028; Discussion: We have previously shown that inhibitory antibody to β1 integrin, AIIB2, leads to selective apoptosis and decreased proliferation in human breast cancer cells in 3DlrECM culture and in vivo. In addition, combining β1 integrin inhibition with IR allowed for reduction of IR dose necessary to achieve growth inhibition in vivo. Here, we show that in HMT3522-T4-2 breast cancer cell line, inhibition of α5 integrin and fibronectin interaction using ATN-161 significantly enhanced apoptosis in 3D lrECM. These data indicate that fibronectin and its receptor, α5β1 are important for survival signaling in breast cancer and may be an important target to enhance radiotherapy efficacy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4126.

Observations of the Askaryan effect in ice

We report on observations of coherent, impulsive radio Cherenkov radiation from electromagnetic showers in solid ice. This is the first observation of the Askaryan effect in ice. As part of the complete validation process for the ANITA experiment, we performed an experiment at the Stanford Linear Accelerator Center in June 2006 using a 7.5 metric ton ice target. We measure for the first time the large-scale angular dependence of the radiation pattern, a major factor in determining the solid-angle acceptance of ultrahigh-energy neutrino detectors.

Cervical cancer patients’ preferences and use of various cancer information sources in South Korea

16073

Background: Accessing appropriate facts is important in enabling cancer patients cope with the disease. This study focused on the utilization and preferences of cancer information sources by cervical cancer patients in terms of ease in receiving and searching the available data. Methods: The study included 830 women over the age of 18 years treated for cervical cancer at six hospitals in South Korea between 1983 and 2004. All the participants provided written informed consent, and the Institutional Review Board of the National Cancer Center approved the protocol. A questionnaire addressed the patients’ use of and preferences for sources and forms of cancer information. Data were collected by mail. Results: Television and/or the radio were the the most frequently cited sources of cancer information by the middle and oldest age groups: 45–64 years (52.0%), =65 years (47.3%), while patients in the youngest age group (<45 years) used the Internet (38.8%). Booklets and/or pamphlets (24.0%) were the source of cancer information preferred by the youngest age group, while patients in the middle and oldest age groups preferred TV/radio: 45–64 years (35.7%) and =65 years (55.0%). Life notes and/or experiences (43.2%), that is, personal accounts, comprised the most easily understood form of information regardless of age group. Conclusions: Our findings indicate that cervical cancer patients’ utilization of and preferences for sources of cancer information vary according to patient age. Tailored educational materials that consider the users’ age and condition should be customized to best fit their specific preferences.

No significant financial relationships to disclose.

Constraints on cosmic neutrino fluxes from the Antarctic Impulsive Transient Antenna experiment

We report new limits on cosmic neutrino fluxes from the test flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day flight of a prototype long-duration balloon payload, called ANITA-lite, in early 2004. We search for impulsive events that could be associated with ultrahigh energy neutrino interactions in the ice and derive limits that constrain several models for ultrahigh energy neutrino fluxes and rule out the long-standing -burst model.

Biosynthesis of phytosterols. Kinetic mechanism for the enzymatic C-methylation of sterols

Cloned soybean sterol methyltransferase was purified from Escherichia coli to gel electrophoretic homogeneity. From initial velocity experiments, catalytic constants for substrates best suited for the first and second C1 transfer activities, cycloartenol and 24(28)-methylenelophenol, were 0.01 and 0.001 s-1, respectively. Two-substrate kinetic analysis using cycloartenol and S-adenosyl-l-methionine (AdoMet) generated an intersecting line pattern characteristic of a ternary complex kinetic mechanism. The high energy intermediate analog 25-azacycloartanol was a noncompetitive inhibitor versus cycloartenol and an uncompetitive inhibitor versus AdoMet. The dead end inhibitor analog cyclolaudenol was competitive versus cycloartenol and uncompetitive versus AdoMet. 24(28)-Methylenecycloartanol and AdoHcy generated competitive and noncompetitive kinetic patterns, respectively, with respect to AdoMet. Therefore, 24(28)-methylenecycloartanol combines with the same enzyme form as does cycloartenol and must be released from the enzyme before AdoHcy. 25-Azacycloartanol inhibited the first and second C1 transfer activities with about equal efficacy (Ki = 45 nm), suggesting that the successive C-methylation of the Delta 24 bond occurs at the same active center. Comparison of the initial velocity data using AdoMet versus [2H3-methyl]AdoMet as substrates tested against saturating amounts of cycloartenol indicated an isotope effect on VCH3/VCD3 close to unity. [25-2H]24(28)-Methylenecycloartanol, [28E-2H]24 (28)-methylenelanosterol, and [28Z-2H]24(28)-methylene lanosterol were prepared and paired with AdoMet or [methyl-3H3]AdoMet to examine the kinetic isotope effects attending the C-28 deprotonation in the enzymatic synthesis of 24-ethyl(idene) sterols. The stereochemical features as well as the observation of isotopically sensitive branching during the second C-methylation suggests that the two methylation steps can proceed by a change in chemical mechanism resulting from differences in sterol structure, concerted versus carbocation; the kinetic mechanism remains the same during the consecutive methylation of the Delta 24 bond.

The effect of the cyclopropyl group on the conformation of chemotactic formyl tripeptides

Certain formyl peptides are powerful chemoattractants towards neutrophils. In this study, several formyl tripeptides were synthesized and used to investigate the effects of different amino acid residues in position 1 on their ability to stimulate neutrophil chemotaxis. Pig neutrophil chemotaxis towards the formyl tripeptide, HCO-Ac(3)C-Leu-Phe-OMe 1, where Ac(3)C represents 1-amino-1-cyclopropane carboxylic acid, was observed. Pig neutrophil chemotaxis towards a very similar formyl tripeptide, HCO-Aib-Leu-Phe-OMe 2, where Aib represents alpha-amino isobutyric acid, was not observed. Compared to the isopropyl group, it was shown that the cyclopropyl group induces a greater percentage of the E conformation about the formamide functionality in these peptides. For 1 and 2, the E isomer distributions in CDCl3 are 36 and 9%, respectively. Since a major difference between these two peptides is the Z/E isomeric distribution, one implication is that the peptide-receptor site interactions involving the E conformer are more effective than those of the Z conformer. No pig neutrophil chemotaxis towards the formyl tripeptides, HCO-Ala-Leu-Phe-OMe 3 and HCO-Gly-Leu-Phe-OMe 4 was observed. These formyl tripeptides exhibit a low percentage of the E isomer, similar to that of peptide 2.