465 research outputs found
Isolation and characterisation of metallothionein from the clam Ruditapes decussatus
Aquatic Toxicology 63 (2003) 307-318Metallothioneins (MT) were obtained after purification from metal-exposed clams (Ruditapes decussatus) using gelpermeation
and ion-exchange chromatography. Four cadmium /metallothioneins (CdMTs) were resolved by ionexchange chromatography and they all had similar molecular weights, high cadmium content and an absorption spectra
indicative of the presence of characteristic Cd /S aggregates. The NH2-terminal sequence suggests the presence of atleast two class I clam MT isoforms. For the other two putative clam CdMTs isolated, the results of the amino acid determination were inconclusive. One was slightly contaminated and the other one had a blocked NH2-terminal. These
clam metalothioneins contain glycine, which seems to be a common feature of molluscan MT family and exhibited more similarity to oysters than to mussels. Further investigation on the inducibility of these isoforms will be necessary if clams are to be used as biomarkers of metal exposure
Long-term cardiovascular risks and statin treatment impact on socioeconomic inequalities: microsimulation model
Background: UK cardiovascular disease (CVD) incidence and mortality have declined in recent decades but socioeconomic inequalities persist. Aims: We present a new CVD model and project health outcomes and impact of guideline-recommended statin treatment across quintiles of socioeconomic deprivation in UK. Design and Setting: Lifetime microsimulation model developed using 117,896 participants in 16 statin trials and 501,854 UK Biobank (UKB) participants and quality of life data from national health surveys. Method: We developed a CVD microsimulation model using risk equations for myocardial infarction, stroke, coronary revascularisation, cancer, vascular and nonvascular death, estimated using trial data. We calibrated and further developed this model in the UKB cohort, including further characteristics and a diabetes risk equation, and validated the model in UKB and Whitehall II cohorts. We used the model to predict CVD incidence, life expectancy, quality-adjusted life years (QALYs) and impact of UK guideline-recommended statin treatment across quintiles of socioeconomic deprivation. Results: Age, sex, socioeconomic deprivation, smoking, hypertension, diabetes and cardiovascular events were key CVD risk determinants. Model-predicted event rates corresponded well to observed rates across participant categories. The model projected strong gradients in remaining life expectancy, with 4-to-5 years (5-to-8 QALYs) gaps between the least and most socioeconomically deprived quintiles. Guideline-recommended statin treatment was projected to increase QALYs with larger gains in quintiles of higher deprivation. Conclusions: The study demonstrated the potential of guideline-recommended statin treatment to reduce socioeconomic inequalities. This CVD model is a novel resource for individualised long-term projections of health outcomes and effects of CVD treatments
Prognostic impact and the relevance of PTEN copy number alterations in patients with advanced colorectal cancer (CRC) receiving bevacizumab
Article first published online: 25 MAR 2013Loss of phosphatase and tensin homologue (PTEN) expression may be prognostic in colorectal cancer (CRC) and may have a correlation with vascular endothelial growth factor (VEGF) expression via hypoxia-inducible factor 1 (HIF-1) alpha, and the PI3K/mTOR pathways. We therefore have explored the prognostic association of PTEN loss and the potential that PTEN loss may be predictive of outcome with bevacizumab. Patients enrolled in the AGITG MAX trial, a randomized Phase III trial of capecitabine (C) +/− bevacizumab (B) (+/− mitomycin C [M]) with available tissues were analyzed for PTEN expression (loss vs. no loss) as assessed using a Taqman® copy number assay (CNA). Of the original 471 patients enrolled, tissues from 302 (64.1%) patients were analyzed. PTEN loss was observed in 38.7% of patients. There was no relationship between PTEN loss and KRAS or BRAF mutation. PTEN status was not prognostic for progression-free survival (PFS) or overall survival (OS) in multivariate analyses adjusting for other baseline factors; loss versus no loss PFS hazard ratio (HR) 0.9 (0.7–1.16), OS HR 1.04 (0.79–1.38). PTEN was not prognostic when assessed by KRAS and BRAF status. By using the comparison of C versus CB+CBM, PTEN status was not significantly predictive of the effectiveness of B for PFS or OS. PTEN status was not prognostic for survival in advanced colorectal cancer, irrespective of KRAS or BRAF status. PTEN status did not significantly predict different benefit with bevacizumb therapy.Timothy J. Price, Jennifer E. Hardingham, Chee K. Lee, Amanda R. Townsend, Joseph W. Wrin, Kate Wilson, Andrew Weickhardt, Robert J. Simes, Carmel Murone & Niall C. Tebbut
Progression-free survival as a surrogate endpoint for overall survival in modern ovarian cancer trials: A meta-analysis
Background: Progression-free survival (PFS) has been adopted as the primary endpoint in many randomized controlled trials, and can be determined much earlier than overall survival (OS). We investigated whether PFS is a good surrogate endpoint for OS in trials of first-line treatment for epithelial ovarian cancer (EOC), and whether this relationship has changed with the introduction of new treatment types.
Methods: In a meta-analysis, we identified summary data [hazard ratio (HR) and median time] from published randomized controlled trials. Linear regression was used to assess the association between treatment effects on PFS and OS overall, and for subgroups defined by treatment type, postprogression survival (PPS) and established prognostic factors.
Results: Correlation between HRs for PFS and OS, in 26 trials with 30 treatment comparisons comprising 24,870 patients, was modest (r2 = 0.52, weighted by trial sample size). The correlation diminished with recency: preplatinum/paclitaxel era, r2 = 0.66; platinum/paclitaxel, r2 = 0.44; triplet combinations, r2 = 0.22; biologicals, r2 = 0.30. The median PPS increased over time for the experimental (Ptrend = 0.03) and control arms (Ptrend = 0.003). The difference in median PPS between treatment arms strongly correlated with the difference in median OS (r2 = 0.83). In trials where the control therapy had median PPS of less than 18 months, correlation between PFS and OS was stronger (r2 = 0.64) than where the median PPS was longer (r2 = 0.48).
Conclusions: In EOC, correlation in the relative treatment effect between PFS and OS in first-line platinum-based chemotherapy randomized controlled trials is moderate and has weakened with increasing availability of effective salvage therapies
The cost effectiveness of bevacizumab when added to capecitabine, with or without mitomycin-C, in first line treatment of metastatic colorectal cancer: results from the Australasian phase III MAX study
Background: Based on the clinical data, bevacizumab has been approved in Australia and globally for the treatment of advanced colorectal cancer. However, limited evidence exists for its cost-effectiveness. The purpose of this study was to evaluate the cost effectiveness of adding bevacizumab to capecitabine monotherapy in patients with metastatic colorectal cancer, using data from the prospective economic evaluation conducted alongside the MAX trial. Methods: Individual patient level data on resource use and progression free survival were prospectively collected in the phase III MAX trial. Resource use data were collected for the period between randomisation and disease progression, and unit costs were assigned from the perspective of the Australian health care funder. Effectiveness was measured in quality adjusted progression free survival years, with utility scores obtained from both the community valued EQ-5D questionnaire and the patient valued UBQ-C questionnaire. Progression free survival was used as a secondary effectiveness measure. Results: The addition of bevacizumab to capecitabine monotherapy cost approximately 135,619 to 149,455 (95% CI, 245,910) when values from the UBQ-C questionnaire were applied. The incremental cost per progression free survival year was 106,703 to $233,225). Conclusions: Bevacizumab was not found to be cost effective at its listed price, based on results from the MAX trial.Roche Products Pty Lt
The cost effectiveness of bevacizumab when added to capecitabine, with or without mitomycin-C, in first line treatment of metastatic colorectal cancer: results from the Australasian phase III MAX study
Background: Based on the clinical data, bevacizumab has been approved in Australia and globally for the treatment of advanced colorectal cancer. However, limited evidence exists for its cost-effectiveness. The purpose of this study was to evaluate the cost effectiveness of adding bevacizumab to capecitabine monotherapy in patients with metastatic colorectal cancer, using data from the prospective economic evaluation conducted alongside the MAX trial. Methods: Individual patient level data on resource use and progression free survival were prospectively collected in the phase III MAX trial. Resource use data were collected for the period between randomisation and disease progression, and unit costs were assigned from the perspective of the Australian health care funder. Effectiveness was measured in quality adjusted progression free survival years, with utility scores obtained from both the community valued EQ-5D questionnaire and the patient valued UBQ-C questionnaire. Progression free survival was used as a secondary effectiveness measure. Results: The addition of bevacizumab to capecitabine monotherapy cost approximately 135,619 to 149,455 (95% CI, 245,910) when values from the UBQ-C questionnaire were applied. The incremental cost per progression free survival year was 106,703 to $233,225). Conclusions: Bevacizumab was not found to be cost effective at its listed price, based on results from the MAX trial.Roche Products Pty Lt
High-Frequency Electrooptic Fabry-Perot Modulators
Electrooptic modulators built from GaAs/AlxGa1-xAs Fabry-Perot cavities operating up to 6.5 GHz are reported. The measured frequency response agrees well with the one predicted using an equivalent circuit model derived from high-speed electrical measurements. The parasitic capacitances have been reduced to approximately 30 fF by fabricating the devices on semi-insulating GaAs substrates and integrating them with on-wafer bound pads which have dimensions compatible with microwave coplanar probes
Acción de la terapia láser sobre la actividad enzimática mitocondrial en un modelo de miopatía experimental.
Las hipótesis sobre el mecanismo de acción del láser de baja intensidad (LLLT: Low Level Laser Teraphy), Helio-Neón (He-Ne) y Arseniuro de Galio (As.Ga), se centran en la mitocondria. Se evaluó el efecto de LLLT en miopatía experimental, valorando la actividad de: citrato sintasa (CI) y los complejos I-IV de la cadena respiratoria mitocondrial (CRM). Se utilizaron 70 ratashembras, cepa Wistar, distribuidas en 7 grupos: A) control, B) injuriado y sacrificado a las 24 hs., C) injuriado y sacrificado a los 10 días, D) injuriado + láser de He-Ne, E) injuriado + láser de As.Ga, F) láser de He-Ne y G) láser de As.Ga. La miopatía se indujo con carragenina, inyectada en un miembro posterior. Las variables fueron determinadas por espectrofotometría. LLLT se realizó durante 10 días consecutivos (9,5 J/cm2).El análisis estadístico se realizó aplicando ANOVA-test de Fisher (p<0.05). El láser de He.Ne por si solo aumentó significativamente (p < 0.05) la actividad de CI y disminuyó la actividad del complejo IV de la CRM (p < 0.05). El láser por si solo aumentó la actividad de CI y disminuyó los complejos II (p<0.001) y IV (0.05). LLLT en miopatía inflamatoria tuvo efecto normo-regulador de la actividad enzimática mitocondrial.Action of laser therapy on mitochondrial enzyme activity in amodel of experimental myopathy.AbstractHypotheses about the mechanism of action of low level laser (LLLT: Low Level Laser therapy), Helium-Neon (He-Ne) and gallium arsenide (As.Ga) focus in the mitochondria. The effect of LLLT in experimental myopathy, evaluating the activity: citrate synthase (CI) and complex I-IV of the mitochondrial respiratory chain (CRM). We used 70 female rats, Wistar strain, divided into 7 groups: A) control, B) injured and sacrificed at 24 hours, C) injured and sacrificed at 10 days, D) injured + He-Ne laser, E) As. Ga injured + laser, F) He-Ne laser and G) laser As.Ga. Myopathy was induced by carrageenan injected into the left hind foot. The variables were determined by spectrophotometry. LLLT was performed for 10 consecutive days (9.5 J/cm2).Statistical analysis was performed using ANOVA-Fisher test (p <0.05). He.Ne laser alone was significantly increased (p <0.05) CI activity and decreased activity of complex IV of the MCA (p <0.05). The laser alone increased CI and decreased activity ofcomplex II (p <0.001) and IV (0.05). LLLT was effective in inflammatory myopathy normal-regulating mitochondrial enzyme activityKey words: Myopathy; Helium Neon laser; Gallium Arsenide laser; Mitochondrial respiratory chai
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