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Biomedical subjects

G Sadler

Publications and source records attributed to G Sadler.

8 recordsLinked to original sources

A 3-year prospective study of the effects of adjuvant treatments on cognition in women with early stage breast cancer.

The neuropsychological performance of 85 women with early stage breast cancer scheduled for chemotherapy, 43 women scheduled for endocrine therapy and/or radiotherapy and 49 healthy control subjects was assessed at baseline (T1), postchemotherapy (or 6 months) (T2) and at 18 months (T3). Repeated measures analysis found no significant interactions or main effect of group after controlling for age and intelligence. Using a calculation to examine performance at an individual level, reliable decline on multiple tasks was seen in 20% of chemotherapy patients, 26% of nonchemotherapy patients and 18% of controls at T2 (18%, 14 and 11%, respectively, at T3). Patients who had experienced a treatment-induced menopause were more likely to show reliable decline on multiple measures at T2 (OR=2.6, 95% confidence interval (CI) 0.823-8.266 P=0.086). Psychological distress, quality of life measures and self-reported cognitive failures did not impact on objective tests of cognitive function, but were significantly associated with each other. The results show that a few women experienced objective measurable change in their concentration and memory following standard adjuvant therapy, but the majority were either unaffected or even improve over time.

Adult↗

Migration of volatile degradation products into ozonated water from plastic packaging materials.

Migration of volatile degradation products from poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE) bottles, polypropylene (PP) caps and ethyl vinyl acetate (EVA) liners into ozonated water was measured. Polymer strips were immersed in deionized and distilled water with ozone concentrations of 0.5, 2.5 and/or 5 mg kg(-1) inside 35-ml vials, which were clamp-sealed and stored at 40 degrees C for 10 days. A purge-and-trap unit was developed to extract volatile products from the ozonated water in vials. The extractables were trapped in an adsorbent tube and analysed using a GC-MS coupled with an automated thermal desorber (ATD). Mass spectra were interpreted by comparison with a NIST mass spectral library, and an internal standard method was used to quantify the extractables of interest. Several volatile compounds found in ozonated water that had been in contact with PP, EVA and HDPE polymers included butanal, pentanal, hexanal, heptanal, octanal, nonanal, 2,2-dimethyl propanal, 3-hexanone, 2-hexanone and heptanone. These compounds could cause off-taste and off-odour with a low organoleptic threshold. In general, the concentrations of these volatile compounds increased with an increased exposure to ozone. The highest concentration found was 14.1 +/- 0.6 microg kg(-1) for hexanal with a 5 mg kg(-1) ozone treatment of PP caps. Even at a treatment level of 5 mg kg(-1) ozone, which is greater than 10 times the current regulatory limits for bottled water, the extractables migrating from those polymers were within the levels permitted by the FDA. For the PET sample, no significant peaks were observed before or after ozonation. These results imply that PP caps containing EVA liners may be major sources of off-odour and taste in ozonated bottled water.

Disinfection↗

Evaluation of e-beam, gamma- and X-ray treatment on the chemistry and safety of polymers used with pre-packaged irradiated foods: a review.

Polymers used to package food intended for irradiation must currently receive separate US FDA approvals for e-beam, gamma and X-radiation. The three forms of irradiation have virtually indistinguishable effects on polymers held in vacuum. However, in air, irradiation damage is favoured by slow dose rates, such as that characteristic of gamma irradiation. Irrespective of irradiation type, theory and existing polymer irradiation literature both suggest that radiolytic products in food contact polymers should not present a health hazard due to migration into the foods they contain. Equations are presented which calculate the FDA allowable content of radiolytic products to achieve 'threshold of regulation' clearance and conversion of radiolytic yield values (G-values) into ppb concentration in the treated polymer in conformance with FDA practice. An approach to quantifying the functional barrier of a polymer is discussed.

Electrons↗

Telephone counseling for smoking cessation: effects of single-session and multiple-session interventions.

Smokers (N = 3,030) were randomized to receive 1 of 3 interventions: (a) a self-help quit kit, (b) a quit kit plus 1 telephone counseling session, or (c) a quit kit plus up to 6 telephone counseling sessions, scheduled according to relapse probability. Both counseling groups achieved significantly higher abstinence rates than the self-help group. The rates for having quit for at least 12 months by intention to treat were 5.4% for self-help, 7.5% for single counseling, and 9.9% for multiple counseling. The 12-month continuous abstinence rates for those who made a quit attempt were 14.7% for self-help, 19.8% for single counseling, and 26.7% for multiple counseling. A dose-response relation was observed, as multiple sessions produced significantly higher abstinence rates than a single session. The first week after quitting seems to be the critical period for intervention.

Adult↗

Evaluating organic compound migration in poly(ethylene terephthalate): a simple test with implications for polymer recycling.

The safety of recycled plastics for food contact use is largely dictated by the ability of post-consumer organic contaminants to absorb into recycled materials and later diffuse from containers made from recycled plastics into the food supply. Diffusion and solubility data for organic contaminants in poly(ethylene terephthalate) (PET) are scarce. An approach for determining permeability constants, diffusion coefficients and solubility constants of slowly migrating contaminants in PET is described. Compounds (neat or in admixture) were heat-sealed in packets made from thin (0.00127 cm) PET films. Packets were placed in containers with GC sampling closures. Headspace (volatile compounds) or an external liquid medium (non-volatile compounds) was analysed for emergence of the compound. Diffusion coefficients were determined from non-steady state diffusion equations, permeability constants were determined from steady state permeation, and solubility constants were calculated from diffusion and permeability values. Diffusion coefficients (25 degrees C) ranged from 10(-9) to < 10(-16) cm2/s. The diffusion coefficient of benzene increased dramatically with concentration. Compounds with high permeation increased the transport rate of slower permeating volatiles.

Conservation of Natural Resources↗