997 resultados para Total toxicity equivalence


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Focal points: ICD-10 codings and spontaneous yellow card reports for warfarin toxicity were compared retrospectively over a one-year period Eighteen cases of ICD-10 coded warfarin toxicity were identified from a total of 55,811 coded episodes More than three times as many ADRs to warfarin were found by screening ICD-10 codes as were reported spontaneously using the yellow card scheme Valuable information is being lost to regulatory authorities and as recognised reporters to the yellow card scheme, pharmacists are well placed to report these ADRs, enhancing their role in the safe and appropriate prescribing of warfarin

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The effects of the antioxidant lipoic acid and its reduced form, dihydrolipoic acid (DHLA), were studied on the process of the erythrocytic toxicity of 4-aminophenol in human erythrocytes in vitro. 4-Aminophenol alone caused a stepwise increase in methaemoglobin formation, along with a commensurate decrease in total thiols. At 10 min., in the presence of lipoic acid alone and the thiol depletor 1-chloro-2,4-dinitrobenzene (CDNB) alone, 4-aminophenol-mediated methaemoglobin formation was significantly increased, whilst thiol levels were significantly reduced compared with the 4-aminophenol alone. At 10 min., with DHLA and CDNB alone, 4-aminophenol was associated with significantly increased methaemoglobin formation. However, thiol levels were not significantly different in the presence of DHLA compared with 4-aminophenol alone, although thiol levels were different compared with control (4-aminophenol alone) in the incubations with CDNB alone. At 15 min., only CDNB/4-aminophenol methaemoglobin formation differed from control, whilst thiol levels were significantly lower in the presence of CDNB alone compared with 4-aminophenol alone. Lipoic acid enhanced the toxicity of 4-aminophenol in terms of increased methaemoglobin formation coupled with increased thiol depletion, whilst DHLA showed increased 4-aminophenol-mediated methaemoglobin formation without thiol depletion. Lipoic acid, and to a lesser extent its reduced derivative DHLA, acted as a prooxidant in the presence of 4-aminophenol, enhancing the oxidative stress effects of the amine in human erythrocytes. © Basic & Clinical Pharmacology & Toxicology 2006.

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The effects of the acidification associated with CO2 leakage from sub-seabed geological storage was studied by the evaluation of the short-term effects of CO2-induced acidification on juveniles of the bivalve Ruditapes philippinarum. Laboratory scale experiments were performed using a CO2-bubbling system designed to conduct ecotoxicological assays. The organisms were exposed for 10 days to elutriates of sediments collected in different littoral areas that were subjected to various pH treatments (pH 7.1; pH 6.6; pH 6.1). The acute pH-associated effects on the bivalves were observed, and the dissolved metals in the elutriates were measured. The median toxic effect pH was calculated, which ranged from 6.33 and 6.45. The amount of dissolved Zn in the sediment elutriates increased in parallel with the pH reductions and was correlated with the proton concentrations. The pH, the pCO2 and the dissolved metal concentrations (Zn and Fe) were linked with the mortality of the exposed bivalves.

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The influence of salinity on Ag toxicity was investigated in Atlantic killifish (Fundulus heteroclitus) early life-stages. Embryo mortality was significantly reduced as salinity increased and Ag(+) was converted to AgCl(solid). However, as salinity continued to rise (>5 ‰), toxicity increased to a level at least as high as observed for Ag(+) in deionized water. Rather than correlating with Ag(+), Fundulus embryo toxicity was better explained (R(2) = 0.96) by total dissolved Ag (Ag(+), AgCl2 (-), AgCl3 (2-), AgCl4 (3-)). Complementary experiments were conducted with medaka (Oryzias latipes) embryos to determine if this pattern was consistent among evolutionarily divergent euryhaline species. Contrary to Fundulus data, medaka toxicity data were best explained by Ag(+) concentrations (R(2) = 0.94), suggesting that differing ionoregulatory physiology may drive observed differences. Fundulus larvae were also tested, and toxicity did increase at higher salinities, but did not track predicted silver speciation. Alternatively, toxicity began to increase only at salinities above the isosmotic point, suggesting that shifts in osmoregulatory strategy at higher salinities might be an important factor. Na(+) dysregulation was confirmed as the mechanism of toxicity in Ag-exposed Fundulus larvae at both low and high salinities. While Ag uptake was highest at low salinities for both Fundulus embryos and larvae, uptake was not predictive of toxicity.

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This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001-10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6-7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity.

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Bevacizumab is considered an established part of the treatment strategies available for schwannomas in patients with Neurofibromatosis Type 2(NF2). In the UK, it is available through NHS National Specialized Commissioning to NF2 patients with a rapidly growing target schwannoma. Regrowth of the tumour on suspension of treatment is often observed resulting in prolonged periods of exposure to bevacizumab to control the disease. Hypertension and proteinuria are common events with bevacizumab use and there are concerns with regards to the long-term risks of prolonged treatment. Dosing, demographic and adverse event(CTCAE 4.03) data from the UK NF2 bevacizumab cohort are reviewed with particular consideration of renal and cardiovascular complications. Eighty patients (48 male:32female), median age 24.5 years (range 11-66years), were followed for a median of 32.7 months (range 12.0–60.2months). The most common adverse events were fatigue, hypertension and infection. A total of 19/80 patients (24%) had either a grade 2 or grade 3 hypertension event and 14/80 patients (17.5%) had proteinuria. Of 36 patients followed for 36 months, 78% were free from hypertension and 86% were free of proteinuria. Logistic regression modeling identified age and induction dosing regime to be predictors of development of hypertension with dose of 7.5mg/kg three weekly and age >30years having higher rates of hypertension. Proteinuria persisted in one of three patients after cessation of bevacizumab. One patient developed congestive heart failure and the details of this case are described. Further work is needed to determine optimal dosing regimes to limit toxicity without impacting on efficacy.

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PURPOSE: To evaluate the addition of cetuximab to neoadjuvant chemotherapy before chemoradiotherapy in high-risk rectal cancer. PATIENTS AND METHODS: Patients with operable magnetic resonance imaging-defined high-risk rectal cancer received four cycles of capecitabine/oxaliplatin (CAPOX) followed by capecitabine chemoradiotherapy, surgery, and adjuvant CAPOX (four cycles) or the same regimen plus weekly cetuximab (CAPOX+C). The primary end point was complete response (CR; pathologic CR or, in patients not undergoing surgery, radiologic CR) in patients with KRAS/BRAF wild-type tumors. Secondary end points were radiologic response (RR), progression-free survival (PFS), overall survival (OS), and safety in the wild-type and overall populations and a molecular biomarker analysis. RESULTS: One hundred sixty-five eligible patients were randomly assigned. Ninety (60%) of 149 assessable tumors were KRAS or BRAF wild type (CAPOX, n = 44; CAPOX+C, n = 46), and in these patients, the addition of cetuximab did not improve the primary end point of CR (9% v 11%, respectively; P = 1.0; odds ratio, 1.22) or PFS (hazard ratio [HR], 0.65; P = .363). Cetuximab significantly improved RR (CAPOX v CAPOX+C: after chemotherapy, 51% v 71%, respectively; P = .038; after chemoradiation, 75% v 93%, respectively; P = .028) and OS (HR, 0.27; P = .034). Skin toxicity and diarrhea were more frequent in the CAPOX+C arm. CONCLUSION: Cetuximab led to a significant increase in RR and OS in patients with KRAS/BRAF wild-type rectal cancer, but the primary end point of improved CR was not met.

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En este articulo se hace un análisis sobre la validez de la TBR (Total Bussines return) como medida de rentabilidad de unidades de negocio que pertenecen a un portafolio corporativo. Se establecen cuales son sus debilidades y en que casos es posible aceptarla como medida de rentabilidad asociada con la creación de valor. Se expone, la coincidencia matemática entre la TBR y el WACC (costo promedio ponderado de capital) a partir del descuento de flujos de caja proyectados y entre el CAV (creación adicional de valor) y la diferencia entre el ingreso económico obtenido y el ingreso económico esperado en un periodo determinado. También se evidencia la equivalencia entre el CAV y la variación del valor de las operaciones más la variación del flujo de caja del periodo. Posteriormente se realiza una aplicación para mostrar como puede utilizar la TBR y la teoría moderna de portafolio para que un gerente corporativo pueda controlar la relación rendimiento-riesgo existente entre las distintas unidades de negocio a cargo de su corporación.

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It has been reported that fetal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes defects in the male reproductive system of the rat. We set out to replicate and extend these effects using a robust experimental design. Groups of 75 (control vehicle) or 55 (50, 200 or 1000 ng of TCDD kg-1 bodyweight) female Wistar(Han) rats were exposed to TCDD on Gestational Day (GD) 15, then allowed to litter. The high dose group dams showed no sustained weight loss compared to control, but four animals had total litter loss. Pups in the high dose group showed reduced body weight up till day 21, and pups in the medium dose group showed reduced body weight in the first week post partum. Balano-preputial separation (BPS) was significantly delayed in the high dose group male offspring. There were no significant effects of treatment when the offspring were subjected to a functional observational battery, or mated with females to assess reproductive capability. 25 males per group were killed on post natal day (PND) 70, and ~60 animals per group (~30 for the high dose group) on PND120 to assess seminology and other endpoints. At PND120, the two highest dose groups showed a statistically significant elevation of sperm counts, compared to control; however, this effect was small (~30%), within the normal range of sperm counts for this strain of rat, was not reflected in testicular spermatid counts nor PND70 data, and is therefore postulated to have no biological significance. Although there was an increase in the proportion of abnormal sperm at PND70, seminology parameters were otherwise unremarkable. Testis weights in the high dose group were slightly decreased at PND 70 and 120, and at PND120, brain weights were decreased in the high dose group, liver to body weight ratios were increased for all three dose groups, with an increase in inflammatory cell foci in the epididymis in the high dose group. These data show that TCDD is a potent developmental toxin after exposure of the developing fetus, but that acute developmental exposure to TCDD on GD15 caused no decrease in sperm counts.

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We have investigated whether fetal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes defects in the male reproductive system of the rat, using chronically exposed rats to ensure continuous exposure of the fetus. 5-6 week old rats were exposed to control diet, or diet containing TCDD, to attain an average dose of 2.4, 8 and 46 ng TCDD kg-1 day-1 for twelve weeks, whereupon the rats were mated, and allowed to litter; rats were switched to control diet after parturition. Male offspring were allowed to develop until kills on PND70 (25 per group), or PND120 (all remaining animals). Offspring from the high dose group showed an increase in total litter loss, and the number of animals alive on post-natal day (PND) 4 in the high dose group was ~26% less than control. The high and medium dose offspring showed decreased weights at various ages. Balano-preputial separation was significantly delayed in all three dose groups, compared to control. There were no significant effects of maternal treatment when the offspring were subjected to a functional observational battery, or learning tests, with the exception that the high dose group showed a deficit in motor activity. 20 rats per group were mated to females, and there were no significant effects of maternal treatment on the fertility of these rats, nor on the F1 or F2 sex ratio. Sperm parameters at PND70 and 120 showed no significant effect of maternal treatment, with the exception that there was an increase in the proportion of abnormal sperm in the high dose group at PND70; this is associated with the developmental delay in puberty in this dose group. There were no remarkable findings of maternal treatment on organ weights, with the exception that testis weights were reduced by ~10% at PND70 (but not PND120), and although the experiment was sufficiently powered to detect small changes, ventral prostate weight was not reduced. There were no significant effects of maternal treatment upon histopathological comparison of high dose and control group organs. These data confirm that developmental exposure to TCDD shows no potent effect on adult sperm parameters or accessory sexual organs, but show that delay in BPS occurs after exposure to low doses of TCDD, and this is dependent upon whether TCDD is administered acutely or chronically.

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The sediments of Bear Creek near Baltimore, Maryland demonstrate substantial toxicity to benthic organisms, and contain a complex mixture of organic and inorganic contaminants. The present study maps the spatial extent and depth profile of toxicity and contamination in Bear Creek, and explores correlations between heavy metals, organic contaminants, and toxic responses. Two novel analytical techniques – handheld XRF and an antibody-based PAH biosensor – were applied to samples from the site to quantify total metals and total PAHs in sediments. By comprehensively assessing toxicity in Bear Creek, the present study provides data to inform future risk assessments and management decisions relating for the site, while demonstrating the benefits of applying joint biological assays and chemical assessment methods to sediments with complex contaminant mixtures.

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The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the Threshold Effect Level values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted. (c) 2005 Elsevier Ltd. All rights reserved.

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This study evaluated the ecotoxicity of five dyes to freshwater organisms before and during their photo-Fenton degradation. EC50 (48h) of the five tested dyes ranged from of 6.9 to >1000mgL(-1) for Daphnia similis. In the chronic tests IC50 (72h) varied from 65 to >100mgL(-1) for Pseudokirchneriella subcapitata and IC50 (8 days) from 0.5 to 410mgL(-1) for Ceriodaphnia dubia. Toxicity tests revealed that although the applied treatment was effective for decolorization of the dye, the partial mineralization may be responsible for the presence of degradation products which can be either more toxic than the original dye, as is the case of Vat Green 3 and Reactive Black 5, lead to initially toxic products which may be further degraded to non toxic products (acid Orange 7 and Food Red 17), or generate non toxic products as in the case of Food Yellow 3. The results highlighted the importance of assessing both acute and chronic toxicity tests of treated sample before effluent discharge.

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Negative-ion mode electrospray ionization, ESI(-), with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was coupled to a Partial Least Squares (PLS) regression and variable selection methods to estimate the total acid number (TAN) of Brazilian crude oil samples. Generally, ESI(-)-FT-ICR mass spectra present a power of resolution of ca. 500,000 and a mass accuracy less than 1 ppm, producing a data matrix containing over 5700 variables per sample. These variables correspond to heteroatom-containing species detected as deprotonated molecules, [M - H](-) ions, which are identified primarily as naphthenic acids, phenols and carbazole analog species. The TAN values for all samples ranged from 0.06 to 3.61 mg of KOH g(-1). To facilitate the spectral interpretation, three methods of variable selection were studied: variable importance in the projection (VIP), interval partial least squares (iPLS) and elimination of uninformative variables (UVE). The UVE method seems to be more appropriate for selecting important variables, reducing the dimension of the variables to 183 and producing a root mean square error of prediction of 0.32 mg of KOH g(-1). By reducing the size of the data, it was possible to relate the selected variables with their corresponding molecular formulas, thus identifying the main chemical species responsible for the TAN values.

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To assess total testosterone and prostatic-specific antigen (PSA) kinetics among diverse chemical castrations, advanced-stage prostate cancer patients were randomized into three groups of 20: Group 1, Leuprolide 3.75 mg; Group 2, Leuprolide 7.5 mg; and Group 3, Goserelin 3.6 mg. All groups were treated with monthly application of the respective drugs. The patients' levels of serum total testosterone and PSA were evaluated at two time periods: before the treatment and 3 months after the treatment. Spearman's rank correlation coefficient was utilized to verify the hypothesis of linear correlation between total testosterone and PSA levels. At the beginning the patients' age, stage, grade, PSA, and total testosterone were similar within the three groups, with median age 72, 70, and 70 years in Groups 1, 2, and 3, respectively. Three months after the treatment, patients who received Leuprolide 7.5 mg presented significantly lower median total testosterone levels compared with Goserelin 3.6 mg and Leuprolide 3.75 mg (9.5 ng/dL vs. 20.0 ng/dL vs. 30.0 ng/dL, respectively; p = .0072), while those who received Goserelin 3.6 mg presented significantly lower PSA levels compared with Leuprolide 7.5 mg and Leuprolide 3.75 mg (0.67 vs. 1.86 vs. 2.57, respectively; p = .0067). There was no linear correlation between total testosterone and PSA levels. Overall, regarding castration levels of total testosterone, 28.77% of patients did not obtain levels ≤50 ng/dL and 47.80% did not obtain levels ≤20 ng/dL. There was no correlation between total testosterone and PSA kinetics and no equivalence among different pharmacological castrations.