Non-small cell lung cancer chemotherapy treatment outcomes and ethnicity: a twenty-year single-centre patterns of care study.

AIM: To investigate the treatment of patients with advanced-stage non-small cell lung cancer (NSCLC) over a 20-year period in a single Aotearoa New Zealand centre with reference to the use of systemic anti-cancer chemotherapy (SACT) and to explore ethnic disparities in treatment and outcomes. METHOD: Using a SACT database maintained by the Oncology Department at Waikato Hospital, Hamilton, Aotearoa New Zealand from 2000 to 2021 we derived summary statistics for patient factors and SACT regimens by ethnicity (Maori and non-Maori). We investigated Kaplan-Meier all-cause survival by ethnicity and SACT. Logistic regression was used to estimate the odds ratios of surviving 12 months and receiving first and second SACT. RESULTS: One thousand and fifty-seven patients with advanced NSCLC were included, with 30% identified as Maori and 53% treated with SACT. The median survival for non-Maori and Maori receiving SACT was 11.9 and 8.5 months respectively (unadjusted odds ratio of surviving 12 months: 1.968; 95% CI: 1.352-2.865; p<0.001). Non-Maori receiving SACT were 86.2% more likely to survive 12 months than Maori. There were no ethnic disparities in the proportion of patients receiving first-line SACT; however, non-Maori were 1.5 times more likely to receive a second SACT than Maori. CONCLUSION: Significant ethnic difference between Maori and non-Maori exists for both survival and receipt of second-line SACT.

Case Report: Sustained Complete Response to PI3K Inhibition in a Patient with Metastatic Breast Cancer Harboring PIK3CA, NF1, and CDH1 Mutations.

PIK3CA mutations resulting in disinhibition of the phosphoinositide 3-kinase (PI3K) pathway are present in approximately a third of estrogen receptor (ER)-positive breast cancer. Recent clinical trials of PI3K inhibition in PIK3CA-mutated metastatic breast cancer have shown improvement in progression-free survival of up to 11 months. We report a 68-year-old woman with metastatic ER-positive breast cancer with PIK3CA mutation who despite having disease progression after four lines of endocrine therapy (ET) attained a complete response (CR) after subsequent addition of a PI3K inhibitor. Remarkably, her CR is still maintained at 5 years. We believe this may be due to the co-occurrence of an NF1 mutation, which increases sensitivity to PI3K inhibition. Our case demonstrates restoration of sensitivity to ET by additional inhibition of PI3K, which resulted in exceptional disease response, far exceeding the expected duration. Hence, we believe that PI3K inhibition in addition to ET should be considered in patients with simultaneous PIK3CA and NF1 mutations.

Reduction reactions and densification during in situ TEM heating of iron oxide nanochains.

The reduction reactions and densification of nanochains assembled from γ-Fe2O3 nanoparticles were investigated using in situ transmission electron microscopy (TEM). Morphological changes and reduction of the metal oxide nanochains were observed during in situ TEM annealing through simultaneous imaging and quantitative analysis of the near-edge fine structures of Fe L2,3 absorption edges acquired by spatially resolved electron energy loss spectroscopy. A change in the oxidation states during annealing of the iron oxide nanochains was observed with phase transformations due to continuous reduction from Fe2O3 over Fe3O4, FeO to metallic Fe. Phase transitions during the in situ heating experiments were accompanied with morphological changes in the nanochains, specifically rough-to-smooth surface transitions below 500 °C, neck formation between adjacent particles around 500 °C, and subsequent neck growth. At higher temperatures, coalescence of FeO particles was observed, representing densification.

Physicochemical properties of iron oxide nanoparticles that contribute to cellular ROS-dependent signaling and acellular production of hydroxyl radical.

While nanoparticles (NPs) are increasingly used in a variety of consumer products and medical applications, some of these materials have potential health concerns. Macrophages are the primary responders to particles that initiate oxidative stress and inflammatory reactions. Here, we utilized six flame-synthesized, engineered iron oxide NPs with various physicochemical properties (e.g. Fe oxidation state and crystal size) to study their interactions with RAW 264.7 macrophages, their iron solubilities, and their abilities to produce hydroxyl radical in an acellular assay. Both iron solubility and hydroxyl radical production varied between NPs depending on crystalline diameter and surface area of the particles, but not on iron oxidation state. Macrophage treatment with the iron oxide NPs showed a dose-dependent increase of heme oxygenase 1 (HO-1) and NAD(P)H:quinone oxidoreductase (NQO-1). The nuclear factor (NF)-erythroid-derived 2 (E2)-related factor 2 (Nrf2) modulates the transcriptional activity of antioxidant response element (ARE)-driven genes, such as HO-1 and NQO-1. Here, we show that the iron oxide NPs activate Nrf2, leading to its increased nuclear accumulation and enhanced Nrf2 DNA-binding activity in NP-treated RAW 264.7 macrophages. Iron solubility and acellular hydroxyl radical generation depend on the physical properties of the NPs, especially crystalline diameter; however, these properties are weakly linked to the activation of cellular signaling of Nrf2 and the expression of oxidative stress markers. Overall, our work shows for the first time that iron oxide nanoparticles induce cellular marker genes of oxidative stress and that this effect is transcriptionally mediated through the Nrf2-ARE signaling pathway in macrophages.

Sublethal effects of CuO nanoparticles on Mozambique tilapia (Oreochromis mossambicus) are modulated by environmental salinity.

The increasing use of manufactured nanoparticles (NP) in different applications has triggered the need to understand their putative ecotoxicological effects in the environment. Copper oxide nanoparticles (CuO NP) are toxic, and induce oxidative stress and other pathophysiological conditions. The unique properties of NP can change depending on the characteristics of the media they are suspended in, altering the impact on their toxicity to aquatic organisms in different environments. Here, Mozambique tilapia (O. mossambicus) were exposed to flame synthesized CuO NP (0.5 and 5 mg · L(-1)) in two environmental contexts: (a) constant freshwater (FW) and (b) stepwise increase in environmental salinity (SW). Sublethal effects of CuO NP were monitored and used to dermine exposure endpoints. Fish exposed to 5 mg · L(-1) CuO in SW showed an opercular ventilation rate increase, whereas fish exposed to 5 mg · L(-1) in FW showed a milder response. Different effects of CuO NP on antioxidant enzyme activities, accumulation of transcripts for metal-responsive genes, GSH ∶ GSSG ratio, and Cu content in fish gill and liver also demonstrate that additive osmotic stress modulates CuO NP toxicity. We conclude that the toxicity of CuO NP depends on the particular environmental context and that salinity is an important factor for modulating NP toxicity in fish.

Arsenic removal from water using flame-synthesized iron oxide nanoparticles with variable oxidation states.

We utilized gas-phase diffusion flame synthesis, which has potential for large-scale production of metal oxide nanoparticles, to produce iron oxide nanoparticles (IONPs) with variable oxidation states. The efficacy of these materials in removal of arsenate (As(V) ) from water was assessed. Two different flame configurations, a diffusion flame (DF) and an inverse diffusion flame (IDF), were employed to synthesize six different IONPs by controlling flame conditions. The IONPs produced in the IDF configuration (IDF-IONPs) had smaller particle diameters (4.8 - 8.2 nm) and larger surface areas (141-213 m2/g) than the IONPs produced in the DF configuration (29 nm, 36 m2/g), which resulted in their higher adsorption capacities. As(V) adsorption capacities of the IDF-IONPs increased when the IONPs were synthesized in more oxidizing conditions. The fully oxidized IDF-IONPs, maghemite (γ-Fe2O3), showed the highest As(V) adsorption capacity, comparable to that of magnetite nanocrystals synthesized by thermal decomposition of iron pentacarbonyl and equivalent to three to four times higher capacity than that of a commonly used goethite-based adsorbent. All IONPs were magnetically responsive, which is of great importance for solid-liquid separation. This study demonstrates that the IONPs synthesized in gas-phase flame, particularly IDF-IONPs, are excellent adsorbents because of their high As(V) sorption capacity, potential for large-scale production, and useful magnetic property.

Ultrasensitive on-chip immunoassays with a nanoparticle-assembled photonic crystal.

Electrophoretic particle entrapment system (EPES) is employed to generate 2D array of nanoparticles coated with biological molecules (i.e., antibodies). Phase matching of the excitation and the emission in the 2D arrays with particles produces a highly enhanced fluorescence signal that was shown to improve the limit of detection in immunoassays. The phase matching is achieved when the particle are in the sub-100 nm range. A comparison between different size particles shows that the sensitivity of an immunoassay is extended to a range that is difficult to achieve with standard technology (e.g., enzyme-linked immunosorbent assay-ELISA). The effectiveness of this novel configuration of particle-in-a-well was demonstrated with an assay for human epidermal growth factor receptor 2 (HER2; breast cancer biomarker), with a detection limit as low as 10 attomolar (aM) in less than 10 µL of serum-based sample. The limit of detection of HER2 indicated far superior assay performance compared to the corresponding standard 96-well plate-based ELISA. The particle-based photonic platform reduces the reagent volume and the time for performing an assay in comparison to competing methods. The simplicity of operation and the level of sensitivity demonstrated here can be used for rapid and early stage detection of biomarkers.

Susceptibility to inhaled flame-generated ultrafine soot in neonatal and adult rat lungs.

Over a quarter of the U.S. population is exposed to harmful levels of airborne particulate matter (PM) pollution, which has been linked to development and exacerbation of respiratory diseases leading to morbidity and mortality, especially in susceptible populations. Young children are especially susceptible to PM and can experience altered anatomic, physiologic, and biological responses. Current studies of ambient PM are confounded by the complex mixture of soot, metals, allergens, and organics present in the complex mixture as well as seasonal and temporal variance. We have developed a laboratory-based PM devoid of metals and allergens that can be replicated to study health effects of specific PM components in animal models. We exposed 7-day-old postnatal and adult rats to a single 6-h exposure of fuel-rich ultrafine premixed flame particles (PFPs) or filtered air. These particles are high in polycyclic aromatic hydrocarbons content. Pulmonary cytotoxicity, gene, and protein expression were evaluated at 2 and 24 h postexposure. Neonates were more susceptible to PFP, exhibiting increased lactate dehydrogenase activity in bronchoalveolar lavage fluid and ethidium homodimer-1 cellular staining in the lung in situ as an index of cytotoxicity. Basal gene expression between neonates and adults differed for a significant number of antioxidant, oxidative stress, and proliferation genes and was further altered by PFP exposure. PFP diminishes proliferation marker PCNA gene and protein expression in neonates but not adults. We conclude that neonates have an impaired ability to respond to environmental exposures that increases lung cytotoxicity and results in enhanced susceptibility to PFP, which may lead to abnormal airway growth.

Age specific responses to acute inhalation of diffusion flame soot particles: cellular injury and the airway antioxidant response.

Current studies of particulate matter (PM) are confounded by the fact that PM is a complex mixture of primary (crustal material, soot, metals) and secondary (nitrates, sulfates, and organics formed in the atmosphere) compounds with considerable variance in composition by sources and location. We have developed a laboratory-based PM that is replicable, does not contain dust or metals and that can be used to study specific health effects of PM composition in animal models. We exposed both neonatal (7 days of age) and adult rats to a single 6-h exposure of laboratory generated fine diffusion flame particles (DFP; 170 µg/m(3)), or filtered air. Pulmonary gene and protein expression as well as indicators of cytotoxicity were evaluated 24 h after exposure. Although DFP exposure did not alter airway epithelial cell composition in either neonates or adults, increased lactate dehydrogenase activity was found in the bronchoalveolar lavage fluid of neonates indicating an age-specific increase in susceptibility. In adults, 16 genes were differentially expressed as a result of DFP exposure whereas only 6 genes were altered in the airways of neonates. Glutamate cysteine ligase protein was increased in abundance in both DFP exposed neonates and adults indicating an initiation of antioxidant responses involving the synthesis of glutathione. DFP significantly decreased catalase gene expression in adult airways, although catalase protein expression was increased by DFP in both neonates and adults. We conclude that key airway antioxidant enzymes undergo changes in expression in response to a moderate PM exposure that does not cause frank epithelial injury and that neonates have a different response pattern than adults.

Alveolar epithelial cell injury due to zinc oxide nanoparticle exposure.

RATIONALE: Although inhalation of zinc oxide (ZnO) nanoparticles (NPs) is known to cause systemic disease (i.e., metal fume fever), little is known about mechanisms underlying injury to alveolar epithelium. OBJECTIVES: Investigate ZnO NP-induced injury to alveolar epithelium by exposing primary cultured rat alveolar epithelial cell monolayers (RAECMs) to ZnO NPs. METHODS: RAECMs were exposed apically to ZnO NPs or, in some experiments, to culture fluid containing ZnCl2 or free Zn released from ZnO NPs. Transepithelial electrical resistance (R(T)) and equivalent short-circuit current (I(EQ)) were assessed as functions of concentration and time. Morphologic changes, lactate dehydrogenase release, cell membrane integrity, intracellular reactive oxygen species (ROS), and mitochondrial activity were measured. MEASUREMENTS AND MAIN RESULTS: Apical exposure to 176 µg/ml ZnO NPs decreased R(T) and I(EQ) of RAECMs by 100% over 24 hours, whereas exposure to 11 µg/ml ZnO NPs had little effect. Changes in R(T) and I(EQ) caused by 176 µg/ml ZnO NPs were irreversible. ZnO NP effects on R(T) yielded half-maximal concentrations of approximately 20 µg/ml. Apical exposure for 24 hours to 176 µg/ml ZnO NPs induced decreases in mitochondrial activity and increases in lactate dehydrogenase release, permeability to fluorescein sulfonic acid, increased intracellular ROS, and translocation of ZnO NPs from apical to basolateral fluid (most likely across injured cells and/or damaged paracellular pathways). CONCLUSIONS: ZnO NPs cause severe injury to RAECMs in a dose- and time-dependent manner, mediated, at least in part, by free Zn released from ZnO NPs, mitochondrial dysfunction, and increased intracellular ROS.

Oxidative injury in the lungs of neonatal rats following short-term exposure to ultrafine iron and soot particles.

Greater risk of adverse effects from particulate matter (PM) has been noted in susceptible subpopulations, such as children. However, the physicochemical components responsible for these biological effects are not understood. As critical constituents of PM, transition metals were postulated to be involved in a number of pathological processes of the respiratory system through free radical-medicated damage. The purpose of this study was to examine whether oxidative injury in the lungs of neonatal rats could be induced by repeated short-term exposure to iron (Fe) and soot particles. Sprague Dawley rats 10 d of age were exposed by inhalation to two different concentrations of ultrafine iron particles (30 or 100 microg/m(3)) in combination with soot particles adjusted to maintain a total particle concentration of 250 microg/m(3). Exposure at 10 d and again at 23 d of age was for 6 h/d for 3 d. Oxidative stress was observed at both Fe concentrations in the form of significant elevations in glutathione disulfide (GSSG) and GSSG/glutathione (GSH) ratio and a reduction in ferric/reducing antioxidant power in bronchoalveolar lavage. A significant decrease in cell viability associated with significant increases in lactate dehydrogenase (LDH) activity, interleukin-1-beta (IL-1beta), and ferritin expression was noted following exposure to particles containing the highest Fe concentration. Iron from these particles was shown to be bioavailable in an in vitro assay using the physiologically relevant chelator, citrate. Data indicate that combined Fe and soot particle exposure induces oxidative injury, cytotoxicity and pro-inflammatory responses in the lungs of neonatal rats.

GAS-PHASE FLAME SYNTHESIS AND PROPERTIES OF MAGNETIC IRON OXIDE NANOPARTICLES WITH REDUCED OXIDATION STATE.

Iron oxide nanoparticles of reduced oxidation state, mainly in the form of magnetite, have been synthesized utilizing a new continuous, gas-phase, nonpremixed flame method using hydrocarbon fuels. This method takes advantage of the characteristics of the inverse flame, which is produced by injection of oxidizer into a surrounding flow of fuel. Unlike traditional flame methods, this configuration allows for the iron particle formation to be maintained in a more reducing environment. The effects of flame temperature, oxygen-enrichment and fuel dilution (i.e. the stoichiometric mixture fraction), and fuel composition on particle size, Fe oxidation state, and magnetic properties are evaluated and discussed. The crystallite size, Fe(II) fraction, and saturation magnetization were all found to increase with flame temperature. Flames of methane and ethylene were used, and the use of ethylene resulted in particles containing metallic Fe(0), in addition to magnetite, while no Fe(0) was present in samples synthesized using methane.

Generation of oxidant response to copper and iron nanoparticles and salts: Stimulation by ascorbate.

The present work describes a two-stage approach to analyzing combustion-generated samples for their potential to produce oxidant stress. This approach is illustrated with the two commonly encountered transition metals, copper and iron. First, their abilities to generate hydroxyl radical were measured in a cell-free, phosphate-buffered saline solution containing ascorbate and/or citrate. Second, their abilities to induce heme oxygenase-1 in cultured human epidermal keratinocytes were assessed in cell culture. Combustion-generated copper oxide nanoparticles were active in both assays and were found to be soluble in culture medium. Depletion of glutathione in the cells or loading the cells with ascorbate greatly increased heme oxygenase-1 induction in the presence of copper. By contrast, iron oxide nanoparticles were active in the phosphate-buffered saline but not in cell culture, and they aggregated in culture medium. Soluble salts of copper and iron exhibited the same contrast in activities as the respective combustion-generated particles. The results suggest that the capability of combustion-generated environmental samples to produce oxidant stress can be screened effectively in a two step process, first in phosphate-buffered saline with ascorbate and subsequently in epithelial cell culture for those exhibiting activity initially. The results also point to an unanticipated interaction in cells of oxidant stress-generating metals with an antioxidant (ascorbate) that is usually missing in culture medium formulations. Thus, ascorbate supplementation of cultured human cells is likely to improve their ability to model the in vivo effects of particulate matter containing copper and other redox-active metals.

Use of focus groups to develop methods to communicate cardiovascular disease risk and potential for risk reduction to people with type 2 diabetes.

BACKGROUND: People need to perceive a risk in order to build an intention-to-change behaviour yet our ability to interpret information about risk is highly variable. OBJECTIVES: We aimed to use a user-centred design process to develop an animated interface for the UK Prospective Diabetes Study (UKPDS) Risk Engine to illustrate cardiovascular disease (CVD) risk and the potential to reduce this risk. In addition, we sought to use the same approach to develop a brief lifestyle advice intervention. METHODS: Three focus groups were held. Participants were provided with examples of materials used to communicate CVD risk and a leaflet containing a draft brief lifestyle advice intervention and considered their potential to increase motivation-to-change behaviours including diet, physical activity, and smoking in order to reduce CVD risk. Discussions were tape-recorded, transcribed and coded and recurring themes sought. RESULTS: Sixty-two percent of participants were male, mean age was 66 years (range = 47-76 years) and median age at leaving full-time education was 18 years (range = 15-40 years). Sixteen had type 2 diabetes and none had a prior history of CVD. Recurring themes from focus group discussions included the following: being less numerate is common, CVD risk reduction is important and a clear visual representation aids comprehension. CONCLUSION: A simple animated interface of the UKPDS Risk Engine to illustrate CVD risk and the potential for reducing this risk has been developed for use as a motivational tool, along with a brief lifestyle advice intervention. Future work will investigate whether use of this interactive version of the UKPDS Risk Engine and brief lifestyle advice is associated with increased behavioural intentions and changes in health behaviours designed to reduce CVD risk.

Environmental aging of polycyclic aromatic hydrocarbons on soot and its effect on source identification.

Soot-associated PAHs were exposed to simulated sunlight to investigate disappearance rates under environmental aging conditions and to examine the robustness of diagnostic ratios for PAH source apportionment. Naphthalene, acenaphthylene, acenaphthene, and fluorene showed an obvious two-phase disappearance in all experiments while phenanthrene and anthracene exhibited this behavior for all but the highest soot loading. The first phase loss is 5-40 times faster than the second phase loss and occurred within 3h for naphthalene, acenaphthylene, acenaphthene, and fluorene and within 10h for phenanthrene and anthracene. Two-phase disappearance was not observed for any of the higher molecular weight PAHs with 4-6 rings. Each PAH has a unique loss rate via photodegradation and volatilization and these rates of some PAHs were affected by soot loadings; phenanthrene and anthracene showed similar rates in the first phase and increased loss rates in the second phase as soot loading increased. In the absence of light, the loss of PAHs was related to both temperature and molecular characteristics. Due to differences in disappearance rates of individual PAHs under illumination over extended times, prolonged exposure to sunlight could change the interpretation of some diagnostic ratios used previously for PAH source identification. This result indicates that more consistent and accurate methods that take into consideration the longevity of particulate PAHs are needed for reliable source apportionment.

Luminescent lanthanide nanoparticles as labels in DNA microarrays for quantification of methyl tertiary butyl ether degrading bacteria.

We report application of lanthanide nanoparticles for DNA quantification in a microarray platform as a substitute for conventional organic fluorophores. A non-PCR based DNA microarray assay for quantifying bacteria capable of biodegrading methyl tertiary-butyl ether (MTBE) was demonstrated. Probe DNA was immobilized on a glass surface, hybridized with biotinylated target DNA and subsequently incubated with Neutravidin-biofunctionalized nanoparticles. The fluorescence spot intensities, measured by a commercial laser scanner, show a linear relationship (R2 = 0.98) with bacterial 16S rDNA over a range of target DNA concentrations, while the background fluorescence remained low. In addition, nanoparticles fluorescence shows a stronger intensity than Quasar570 (Cy3). Present sensitivity of the assay is 10 pM of target DNA. The selectivity of the DNA-nanoparticle-probes to discriminate a non-target DNA with two base pairs mismatch in the 16S rDNA gene sequence was shown. The use of Eu:Gd2O3 nanoparticles as biolabels provides a relatively non-toxic, inexpensive, rapid and sensitive alternative to the materials currently used in DNA microarrays.

Mechanisms of particulate matter toxicity in neonatal and young adult rat lungs.

Particulate matter (PM*) has been associated with a variety of adverse health effects, primarily involving the cardiovascular and respiratory systems. Researchers continue to investigate biologic mechanisms that may explain how exposure to PM exacerbates or directly causes adverse effects. Particle composition may play a critical role in these effects. In this study we used a diffusion flame system to generate ultrafine iron, soot, and iron combined with soot particles and exposed young adult and neonatal rats to different compositions of these particles. Young adult rats inhaled all three PM compositions on three consecutive days for 6 hours per day. Exposure to soot PM at 250 microg/m3 or to iron PM at 57 microg/m3 demonstrated no adverse respiratory effects. However, we observed mild pulmonary stress when the iron concentration was increased to 90 microg/m3. The most striking effects resulted when the rats inhaled PM composed of iron (45 microg/m3) combined with soot particles (total mass 250 microg/m3). This type of exposure produced significant indicators of oxidative stress, signs of inflammation, and increases in the levels of cytochrome P450 isozymes in the lungs. Repeated three-day exposure of neonatal rats to soot and iron particles in the second and the fourth weeks of life produced significant oxidative stress (elevations in oxidized and reduced glutathione) and ferritin induction. Neonatal rats exposed to PM in the second week of life also had a subtle but significant cell proliferation reduction in the centriacinar regions of the lungs. These findings suggest that iron combined with soot PM can lead to changes in the respiratory tract not found with exposure to iron or soot PM alone at similar concentrations. Unique effects in the neonate suggest that age may play an important role in susceptibility to inhaled particles.

Visual manifestations of craniofrontonasal dysplasia.

In this sample of craniofrontonasal dysplasia, a 44.4% prevalence of visual impairment was observed, with more than half being due to potentially correctable causes of visual loss, including amblyopia and anisometropia. High prevalences of strabismus (88.9%) and V-pattern (55.5%) in craniofrontonasal dysplasia were also demonstrated. All three patients who underwent strabismus surgery showed improvement in ocular alignment postoperatively. This group needs regular eye examinations to assess for visual impairment and provide timely intervention for modifiable causes of visual loss.