Charge Transient Spectroscopy Study Of Deep Centers In Cvd Diamond And Diamond-Like Films

The parameters of trapping centers in CVD diamond and Diamond-Like Carbon (DLC) films were studied by Charge Deep Level Transient Spectroscopy (Q-DLTS). The concentrations, activation energies, captures cross-section and location of the trapping centers were determined. The influence of post deposition heat treatment on the defect center parameters was studied. The Q-DLTS measurements showed that micro defects are acting as point trapping centers and have the continuous energy spectrum with one or two maximums at different energies. The nature of the trapping centers is discussed.

Expression of epidermal growth factor receptor (EGFR) and Ki67 in feline oral squamous cell carcinomas (FOSCC)

The aims of this study were to establish expression of epidermal growth factor receptor (EGFR) and Ki67 in 67 archived biopsy samples of feline oral squamous cell carcinomas (FOSCCs) and to establish if the expression of either markers was predictive of survival. Samples were immunohistochemically labelled for the two proteins and scored. Statistical analyses of data, including Kaplan-Meier survival curves, were performed. All samples expressed both markers although levels differed between samples. Median overall survival was 46 days and 1-year survival was 5%. There was no correlation between Ki67 and EGFR scores (Pearson's correlation coefficient, P = 0.861). Low cellular proliferation (low Ki67 score) was positively correlated with an overall longer survival (Log Rank, P = 0.02) and a trend towards better survival for the high EGFR group was observed (Log Rank, P = 0.076). Ki67 and EGFR immunostaining in FOSCC may be of value as biochemical markers for screening of biopsies from cases of FOSCC.

Locoregional intravascular viral therapy of cancer: precision guidance for Paris's arrow?

Viral therapy of cancer includes strategies such as viral transduction of tumour cells with 'suicide genes', using viral infection to trigger immune-mediated tumour cell death and using oncolytic viruses for their direct anti-tumour action. However, problems still remain in terms of adequate viral delivery to tumours. A role is also emerging for single-organ isolation and perfusion. Having begun with the advent of isolated limb perfusion for extremity malignancy, experimental systems have been developed for the perfusion of other organs, particularly the liver, kidneys and lungs. These are beginning to be adopted into clinical treatment pathways. The combination of these two modalities is potentially significant. Locoregional perfusion increases the exposure of tumour cells to viral agents. In addition, the avoidance of systemic elimination through the immune and reticulo-endothelial systems should provide a mechanism for increased transduction/infection of target cells. The translation of laboratory research to clinical practice would occur within the context of perfusion programmes, which are already established in the clinic. Many of these programmes include the use of vasoactive cytokines such as tumour necrosis factor-alpha, which may have an effect on viral uptake. Evidence of activation of specific anti-tumour immunological responses by intratumoural and other existing methods of viral administration raises the intriguing possibility of a locoregional therapy, with the ability to affect distant sites of disease. In this review, we examined the state of the literature in this area and summarized current findings before indicating likely areas of continuing interest.

Urine PGE-M to assess prostaglandin E2 (PGE2) levels in non-small cell lung cancer (NSCLC)

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Background: COX-2 is often overexpressed in NSCLC leading to high systemic PGE2 levels that in turn play a role in NSCLC pathogenesis. Changes in urine PGE-M (the major PGE2 metabolite) reflect changes in systemic & intratumoral PGE2 [Csiki et al. Clin Cancer Res 11:6634, 2005]. A ≥70% decline in PGE-M in NSCLC patients (pts) treated with celecoxib (C) (400 mg bid) + docetaxel (D) was associated with an apparent survival benefit [Ibid]. To effect maximum COX-2 inhibition we tested a higher C dose in a subsequent phase II trial. Methods: Eligibility: previously treated NSCLC, PS 0–2, evaluable/measurable disease, adequate marrow, renal & hepatic function, no current NSAID or sulfa allergy. Urine PGE-M measured prior to & 5–10 days after C 600 mg PO bid. Pts with ≥70% decline in PGE-M continued on C + D 75 mg/m2 or pemetrexed 500 mg/m2 q3wk x 4 cycles followed by maintenance C 400 mg PO bid until PD or drug intolerance. Results: 21 pts enrolled; F=7, M=14; 2 ineligible (1 carcinoid; 1 elevated LFT); 2 stopped C early (1 ARF; 1 pruritus). Mean PGE-M levels decreased from 38.9 to 7.8 ng/mg Cr pre- & post-C (mean change = 80%; P=0.002). The mean decline was greater in current & former smokers (81%; P=0.002) compared to never smokers (46%; P=0.19). Males had higher pre- treatment PGE-M (44 vs. 28.8 ng/mg Cr; P=0.21). Males had a significant decrease in mean PGE-M levels after C (78%; P=0.011); a similar albeit not significant change occurred in females (P=0.12). 12 screened pts (57%) had a ≥70% decline in PGE-M & received treatment with C + chemotherapy; 8 pts are evaluable for response; SD = 6; PD = 2. Treatment was well tolerated with no cardiac toxicities noted. Conclusions: These preliminary data indicate C 600 mg bid effectively inhibits intratumoral COX-2 in >50% NSCLC pts, a higher percentage than our previous trial using C 400 mg bid. The effect is greatest in former & current smokers & males compared to never smokers & females. Toxicities are acceptable. Accrual is ongoing. [Funding: VICC Lung Cancer SPORE CA90949].

No significant financial relationships to disclose.

Enrollment of lung cancer patients on clinical trials at an NCI comprehensive cancer center

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Background: Enrollment of cancer patients (pt) in clinical trials is considered essential in order to improve cancer care. However, cancer clinical trials participation remains low. Understanding barriers to pt enrollment is necessary to overcome this problem. Previous reports have identified pt age, race, and ethnicity, disease stage, performance status (PS) and relationship with their health care provider as factors that can influence the enrollment of pts in clinical trials. Methods: We conducted a retrospective review of the charts of all lung cancer pts seen in the Thoracic Oncology Clinic at Vanderbilt Ingram Cancer Center between November 2005 and November 2008. A total of 1075 lung cancer pts were seen. Results: 577 charts (of a planned 1075) have been audited to date. Pt demographics: median age = 64 yrs; male = 54%; Caucasian = 92%, African American = 4%, and Asian = 1%; NSCLC = 80%, SCLC = 17%. Male pts were more likely than females to be eligible for a clinical trial (p = 0.056). A study protocol was available for 57% of pts; 52% of pts proved eligible; 36% were entered into a study (11% total population). Significantly more protocols were available for NSCLC pts compared to pts with SCLC (p ≤ 0.001); there was also a non-significant trend towards higher enrollment of eligible NSCLC pts. There was no difference in eligibility between ethnicity; the percentage of eligible pts enrolling on trials was similar between Caucasian & African American pts (46% and 43%); no Asian pts were enrolled. The most common reasons for not enrolling included a preference for treatment closer to home (29%), patient refusal (19%), PS (19%), and co-morbidities (17%). The distance pts traveled was inversely correlated with likelihood of study participation. Conclusions: A total of 11% of lung cancer pt evaluated in our Thoracic Oncology Clinic were enrolled in clinical trials. Our data suggest additional strategies are needed to attract minority groups, increase enrollment of women and pts with comorbidities and poor PS. Travel distances influence pt willingness to participate in clinical trials. Strategies are needed to overcome this factor.

No significant financial relationships to disclose.

Toxicity Assessment of Industrial Chemicals and Airborne Contaminants: Transition fromIn VivotoIn VitroTest Methods: A Review

Exposure to occupational and environmental contaminants is a major contributor to human health problems. Inhalation of gases, vapors, aerosols, and mixtures of these can cause a wide range of adverse health effects, ranging from simple irritation to systemic diseases. Despite significant achievements in the risk assessment of chemicals, the toxicological database, particularly for industrial chemicals, remains limited. Considering there are approximately 80,000 chemicals in commerce, and an extremely large number of chemical mixtures, in vivo testing of this large number is unachievable from both economical and practical perspectives. While in vitro methods are capable of rapidly providing toxicity information, regulatory agencies in general are still cautious about the replacement of whole-animal methods with new in vitro techniques. Although studying the toxic effects of inhaled chemicals is a complex subject, recent studies demonstrate that in vitro methods may have significant potential for assessing the toxicity of airborne contaminants. In this review, current toxicity test methods for risk evaluation of industrial chemicals and airborne contaminants are presented. To evaluate the potential applications of in vitro methods for studying respiratory toxicity, more recent models developed for toxicity testing of airborne contaminants are discussed.

High resolution energy analyzer for broad ion beam characterization

Characterization of the ion energy distribution function (IEDF) of low energy high current density ion beams by conventional retarding field and deflection type energy analyzers is limited due to finite ion beam emittance and beam space charge spreading inside the analyzer. These deficiencies are, to a large extent, overcome with the recent development of the variable-focusing retarding field energy analyzer (RFEA), which has a cylindrical focusing electrode preceding the planar retarding grid. The principal concept of this analyzer is conversion of a divergent charged particle beam into a quasiparallel beam before analyzing it by the planar retarding field. This allows analysis of the beam particle total kinetic energy distribution with greatly improved energy resolution. Whereas this concept was first applied to analyze 5-10 keV pulsed electron beams, the present authors have adapted it to analyze the energy distribution of a low energy (<or=1 KeV) broad ion beam. In this paper we describe the RFEA design, which was modified from the original, mainly as required by the specifics of broad ion beam energy analysis, and the device experimental characterization and modeling results. Among the modifications, an orifice electrode placed in front of the RFEA provides better spatial resolution of the broad ion beam ion optics emission region and reduces the beam plasma density in the vicinity of analyzer entry. An electron repeller grid placed in front of the RFEA collector was found critical for suppressing secondary electrons, both those incoming to the collector and those released from its surface, and improved energy spectrum measurement repeatability and accuracy. The use of finer mesh single- and double-grid retarding structures reduces the retarding grid lens effect and improves the analyzer energy resolution and accuracy of the measured spectrum mean energy. However, additional analyzer component and configuration improvements did not further change the analyzed IEDF shape or mean energy value. This led us to conclude that the optimized analyzer construction provides an energy resolution considerably narrower than the investigated ion beam energy spectrum full width at half maximum, and the derived energy spectrum is an objective and accurate representation of the analyzed broad ion beam energy distribution characteristics. A quantitative study of the focusing voltage and retarding grid field effects based on the experimental data and modeling results have supported this conclusion.

Multivariable analysis comparing outcome after sentinel node biopsy or therapeutic lymph node dissection in patients with melanoma (Br J Surg 2007; 94: 1293-1299)

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Comparative in vitro cytotoxicity assessment of selected gaseous compounds in human alveolar epithelial cells

Exposure to airborne contaminants is significantly associated with human health risks, ranging from bronchial reactivity to morbidity and mortality due to acute intense or long term low level repeated exposures. However, the precise mechanisms that derive such effects are not always understood. Although inhalation studies are technologically complicated, correct hazard characterisation is essential for comparable risk assessment of inhaled materials. The aim of this study was to investigate the comparative in vitro cytotoxicity of selected gaseous contaminants in human lung cells. The cytotoxicity of nitrogen dioxide (NO(2)), sulphur dioxide (SO(2)) and ammonia (NH(3)) was investigated in A549- human pulmonary type II-like epithelial cell lines cultured on porous membranes in Snapwell inserts. A dynamic direct exposure method was established by utilizing the horizontal diffusion chamber system (Harvard Apparatus Inc, USA) for delivery of test atmospheres. Test atmospheres were generated using a dynamic direct dilution method and the concentration monitored by appropriate analytical methods. A diversified battery of in vitro assays including the MTS (tetrazolium salt; Promega), NRU (neutral red uptake; Sigma) and ATP (adenosine triphosphate; Promega) assays was implemented. Airborne IC(50) (50% inhibitory concentration) values were calculated based on the most sensitive assay for each test gas including NO(2) (IC(50)=11+/-3.54 ppm; NRU)>SO(2) (IC(50)=48+/-2.83 ppm; ATP)> and NH(3) (IC(50)=199+/-1.41 ppm; MTS). However, all in vitro assays revealed similar toxicity ranking for selected gaseous contaminants. Identical toxicity ranking was achieved using both in vitro and published in vivo data. This comparison suggests that results of in vitro methods are comparable to in vivo data and may provide greater sensitivity for respiratory toxicity studies of gaseous contaminants.