Vibrational spectroscopy for cervical cancer pathology, from biochemical analysis to diagnostic tool.

Cervical cancer is the second most common cancer in women worldwide with 80% of cases arising in the developing world. The mortality associated with cervical cancer can be reduced if this disease is detected at the early stages of development or at the pre-malignant state (cervical intraepithelial neoplasia, CIN). The aim of this study was to investigate the potential of Raman spectroscopy as a diagnostic tool to detect biochemical changes accompanying cervical cancer progression.

Spectroscopic characterization of novel polycyclic aromatic polymers.

A series of novel polyphenylenevinylene (PPV) derivative polymers were studied by absorption and photoluminescence spectroscopies. The effect of the sequential introduction of polycyclic aromatic ring substituents into the delocalized backbone was examined with relation to hypsochromatic and bathochromatic shifting. While the replacement of the phenyl units by naphthyl units results in a substantial hypsochromic shift of both the absorption and emission spectra, their subsequent substitution by anthryl units results in a bathochromic shift.

In vitro toxicity evaluation of single walled carbon nanotubes on human A549 lung cells.

This paper describes the in vitro cytotoxicity assessment of single walled carbon nanotubes (SWCNT) on A549 cells, a human lung cell line. Cellular viability was determined using the alamar blue (AB), neutral red (NR) and MTT assays, which evaluated metabolic, lysosomal and mitochondrial activity respectively. In addition, the total protein content of the cells was measured using the coomassie brilliant (CB) blue assay.

The release of bystander factor(s) from tissue explant cultures of rainbow trout (Onchorhynchus mykiss) after exposure to gamma radiation.

The bystander response has been documented in cell lines and cell cultures derived from aquatic species over the past several years. However, little work has been undertaken to identify a similar bystander response in tissue explant cultures from fish. In this study, indirect effects of ionizing gamma radiation on tissue explant cultures of fish were investigated.

Bundling and diameter selectivity in HiPco SWNTs poly(p-phenylene vinylene-co-2,5-dioctyloxy-m-phenylene vinylene) composites.

Temperature-dependent (TD) Raman measurements at laser excitation 514.5 nm were performed at different concentrations. The spectral profile of the radial breathing modes were investigated up to a polymer concentration of 1 g/L and were found to be dominated by approximately 1.

Structure-property relationships for electron-vibrational coupling in conjugated organic oligomeric systems.

A series of pi-conjugated oligomers containing one to six monomer units were studied by absorption and photoluminescence spectroscopy. As is common for these systems, a linear relationship between the positioning of the lowest-energy absorption and the highest-energy photoluminescence maxima plotted versus inverse conjugation length is observed, in good agreement with a simple nearly free electron model, one of the earliest descriptions of the properties of one-dimensional organic molecules. It was observed that the Stokes shift and therefore Huang-Rhys factor also exhibit a well-defined relationship with increasing conjugation length, implying a correlation between the electron-vibrational coupling and chain length.

Temperature-induced nucleation of poly(p-phenylene vinylene-co-2,5-dioctyloxy-m-phenylene vinylene) crystallization by HiPco single-walled carbon nanotubes.

Hybrid systems of the conjugated organic polymer poly(p-phenylene vinylene-co-2,5-dioctyloxy-m-phenylene vinylene)(PmPV) and HiPco single-walled carbon nanotubes (SWNTs) are explored using spectroscopic and thermal techniques to determine specific interactions. Vibrational spectroscopy indicates a weak interaction, and this is further elucidated using differential scanning calorimetry (DSC), confocal laser scanning microscopy, temperature-dependent Raman spectroscopy, and temperature-dependent infrared spectroscopy of the raw materials and the composite. An endothermic transition is observed in the DSC of both the polymer and the 0.

Apoptosis is initiated in human keratinocytes exposed to signalling factors from microbeam irradiated cells.

Purpose: There is now no doubt that bystander signalling from irradiated cells occurs and causes a variety of responses in cells not targeted by the ionizing track. However, the mechanisms underlying these processes are unknown and the relevance to radiotherapy and risk assessment remains controversial. Previous research by our laboratory has shown bystander effects in a human keratinocyte cell line, HPV-G cells, exposed to medium from gamma irradiated HPV-G cells.

In vitro cytotoxicity assessment of the biocidal agents sodium o-phenylphenol, sodium o-benzyl-p-chlorophenol, and sodium p-tertiary amylphenol using established fish cell lines.

The cytotoxicity of three biocidal agents frequently employed as active ingredients in phenolic-based disinfectants, were evaluated in three established fish cell lines (EPC, CHSE and RTG-2). Cell viability was assessed using two fluorescent indicator dyes, Alamar Blue for metabolism and neutral red for lysosomal activity. Total protein content was also quantified as a measure of cell detachment.

The involvement of calcium and MAP kinase signaling pathways in the production of radiation-induced bystander effects.

Much evidence now exists regarding radiation-induced bystander effects, but the mechanisms involved in the transduction of the signal are still unclear. The mitogen-activated protein kinase (MAPK) pathways have been linked to growth factor-mediated regulation of cellular events such as proliferation, senescence, differentiation and apoptosis. Activation of multiple MAPK pathways such as the ERK, JNK and p38 pathways have been shown to occur after exposure of cells to radiation and a variety of other toxic stresses.

In-depth study into the interaction of single walled carbon nanotubes with anthracene and p-terphenyl.

Solubilization of single walled carbon nanotubes (SWNT) in the presence of polycyclic aromatic hydrocarbons (PAHs) such as p-terphenyl and anthracene has been shown. The suspensions formed are stable for periods greater than 48 months but to date experimental research is scarce regarding the interactions that are taking place. Spectroscopic analysis such as Raman and fluorescence are used to probe the interactions occurring between the PAHs and the SWNT over a wide concentration range.

Cellular responses in primary epidermal cultures from rainbow trout exposed to zinc chloride.

In this study, we examined the effects of zinc chloride (ZnCl(2)) (0-200mg/L) on primary epidermal cultures from Oncorhynchus mykiss. Increases in the rate and amount of mucus released were detected post-exposure, as was a dose-dependent increase in the synthesis of acidic glycoproteins. The cytotoxicity of ZnCl(2) to the cultures was significantly increased (P< or =0.

A novel sensor array for field based ocular ultraviolet radiation measurements.

The intensification of terrestrial solar ultraviolet radiation (UVR) due to the diminution of the ozone layer has promoted a variety of research into establishing the impact of this elevated potential dose of UVR on biological tissues. Certain anterior ocular tissues have been found to be susceptible to damage by incident UVR and potentially blinding diseases such as pterygium are thought to be a direct result of absorbed UVR at the nasal limbus. There is a need for more accurate quantification and localisation of incident UVR at the anterior ocular surface.

A test battery approach for the ecotoxicological evaluation of estuarine sediments.

The purpose of this study was to evaluate the overall sensitivity and applicability of a number of bioassays representing multiple trophic levels, for the preliminary ecotoxicological screening (Tier I) of estuarine sediments. Chemical analyses were conducted on sediments from all sampling sites to assist in interpreting results. As sediment is an inherently complex, heterogeneous geological matrix, the toxicity associated with different exposure routes (solid, porewater and elutriate phases) was also assessed.

Mitochondrial DNA point mutations and a novel deletion induced by direct low-LET radiation and by medium from irradiated cells.

Radiation damage incurred by nuclear DNA is well documented and interest is increasing in the properties of 'bystander' factor(s) and their ability to induce radiation-like damage in cells never exposed to radiation. 'Bystander' and direct low-LET radiation effects on the mitochondria, and more particularly the mitochondrial genome are less well understood. In this study HPV-G cells (a human keratinocyte cell line derived from human neonatal foreskin transfected with the HPV-16 virus) were exposed to either gamma-radiation doses as low as 5 mGy and up to 5 Gy from a 60Co teletherapy unit, or to growth medium taken from similarly irradiated cells, i.

Identification of a multixenobiotic resistance mechanism in primary cultured epidermal cells from Oncorhynchus mykiss and the effects of environmental complex mixtures on its activity.

Multixenobiotic resistance (MXR) is a mechanism analogous to the mammalian multidrug resistance (MDR) phenotype, whereby, simultaneous resistance is conferred against the intracellular accumulation of structurally and functionally diverse, natural, endogenous and environmental toxicants. Expression of P-glycoproteins (P-gp), ATP-dependent transporters encoded for by the mdr1 gene that have been implicated in this xenobiotic efflux mechanism, have previously been detected in normal teleost tissues involved in a secretory, absorption or a barrier function. The presence of these proteins in the epidermis of fish species has not to our knowledge previously been investigated.

Assessing the potential of fish cell lines as tools for the cytotoxicity testing of estuarine sediment aqueous elutriates.

In the present study, we assess the potential of fish cell lines (CHSE, EPC and RTG-2) to be used as screening tools for the ecotoxicological assessment of estuarine sediments. The processing of sediment to a form suitable for in vitro exposure is an inherent problem when using cell cultures. The approach employed in this study was to prepare aqueous elutriate extracts from whole sediments, which were subsequently used to reconstitute powdered media.