995 resultados para Toxicity Tests


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Seed from the sensitive wheat (Triticum aestivumL.) cultivar Anahuac was treated to gamma-ray irradiation and eleven Al3+ tolerant mutants selected. The objective was to compare these mutants to the original Anahuac and to the tolerant wheat cultivars IAC-24 and IAC-60 from 1994 to 1996 in acid (Capão Bonito) and limed (Monte Alegre do Sul) soil field trials, in the State of São Paulo, Brazil. Grain yield and agronomic characteristics were analyzed. All the mutant lines yielded higher than the sensitive Anahuac cultivar in the acid soils of Capão Bonito. Under limed soil conditions, 10 mutants had a similar yield to the original sensitive cultivar and one a lower yield. The majority of the mutants were similar in yield to the tolerant cultivars IAC-24 and IAC-60 under both conditions. Some of the mutants showed altered agronomic characteristics, but these alterations did not generally influence the grain yield. The results indicated that tolerant lines with good characteristics may be obtained from a susceptible cultivar by mutation induction, thus allowing cropping under conditions where Al3 + is a limiting factor.

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As a result of the construction of the Saylorville Dam and Reservoir on the Des Moines River, six highway bridges are scheduled for removal. Five of these are old high-truss single-lane bridges, each bridge having several simple spans. The other bridge is a fairly modern (1955) double 4-span continuous beam-and-slab composite highway bridge. The availability of these bridges affords an unusual opportunity for study of the behavior of full-scale bridges. Because of the magnitude of the potential testing program, a feasibility study was initiated and the results are presented in this two-part final report. Part I summarizes the findings and Part II presents the supporting detailed information.

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Many rapid diagnostic tests (RDT) for the diagnosis of infectious diseases have been developed over the last 20 years. These allow (1) administering a treatment immediately in case of a potentially fatal disease, (2) prescribing a specific rather than presumptive treatment, (3) quickly introducing measures aimed at interrupting the transmission of the disease, (4) avoiding useless antibiotic treatments and (5) implementing a sequential diagnostic strategy to avoid extensive investigations. Using the example of malaria, a new strategy that includes a RDT as first-line emergency diagnostic tool and, when negative, delayed microscopy at the laboratory opening time is implemented in Lausanne since 1999. This strategy has been shown to be safe. Each TDR has its own characteristics that imperatively need to be known by the practitioner if he/she wants to use it in a rational way.

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To cite this article: Ponvert C, Perrin Y, Bados-Albiero A, Le Bourgeois M, Karila C, Delacourt C, Scheinmann P, De Blic J. Allergy to betalactam antibiotics in children: results of a 20-year study based on clinical history, skin and challenge tests. Pediatr Allergy Immunol 2011; 22: 411-418. ABSTRACT: Studies based on skin and challenge tests have shown that 12-60% of children with suspected betalactam hypersensitivity were allergic to betalactams. Responses in skin and challenge tests were studied in 1865 children with suspected betalactam allergy (i) to confirm or rule out the suspected diagnosis; (ii) to evaluate diagnostic value of immediate and non-immediate responses in skin and challenge tests; (iii) to determine frequency of betalactam allergy in those children, and (iv) to determine potential risk factors for betalactam allergy. The work-up was completed in 1431 children, of whom 227 (15.9%) were diagnosed allergic to betalactams. Betalactam hypersensitivity was diagnosed in 50 of the 162 (30.9%) children reporting immediate reactions and in 177 of the 1087 (16.7%) children reporting non-immediate reactions (p < 0.001). The likelihood of betalactam hypersensitivity was also significantly higher in children reporting anaphylaxis, serum sickness-like reactions, and (potentially) severe skin reactions such as acute generalized exanthematic pustulosis, Stevens-Johnson syndrome, and drug reaction with systemic symptoms than in other children (p < 0.001). Skin tests diagnosed 86% of immediate and 31.6% of non-immediate sensitizations. Cross-reactivity and/or cosensitization among betalactams was diagnosed in 76% and 14.7% of the children with immediate and non-immediate hypersensitivity, respectively. The number of children diagnosed allergic to betalactams decreased with time between the reaction and the work-up, probably because the majority of children with severe and worrying reactions were referred for allergological work-up more promptly than the other children. Sex, age, and atopy were not risk factors for betalactam hypersensitivity. In conclusion, we confirm in numerous children that (i) only a few children with suspected betalactam hypersensitivity are allergic to betalactams; (ii) the likelihood of betalactam allergy increases with earliness and/or severity of the reactions; (iii) although non-immediate-reading skin tests (intradermal and patch tests) may diagnose non-immediate sensitizations in children with non-immediate reactions to betalactams (maculopapular rashes and potentially severe skin reactions especially), the diagnostic value of non-immediate-reading skin tests is far lower than the diagnostic value of immediate-reading skin tests, most non-immediate sensitizations to betalactams being diagnosed by means of challenge tests; (iv) cross-reactivity and/or cosensitizations among betalactams are much more frequent in children reporting immediate and/or anaphylactic reactions than in the other children; (v) age, sex and personal atopy are not significant risk factors for betalactam hypersensitivity; and (vi) the number of children with diagnosed allergy to betalactams (of the immediate-type hypersensitivity especially) decreases with time between the reaction and allergological work-up. Finally, based on our experience, we also propose a practical diagnostic approach in children with suspected betalactam hypersensitivity.

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Selostus: Seleenin myrkytysoireet juurissa

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PURPOSE: To evaluate the antimitotic and toxic effects of 5-chlorouracil (5-CU) and 5-fluorouracil (5-FU) and study their potential to delay filtering bleb closure in the rabbit eye when released by poly(ortho esters) (POE). METHODS: Rabbit Tenon fibroblasts and human conjunctival cells were incubated with various 5-CU and 5-FU concentrations. Antiproliferative effects and toxicity were evaluated at 24 and 72 hours by monotetrazolium, neutral red, and Hoechst tests and cell counting. Mechanisms of cell death were evaluated using TUNEL assay, annexin V binding, immunohistochemistry for anti-apoptosis-inducing factor (AIF) and LEI/L-DNase II. Trabeculectomy was performed in pigmented rabbits. Two hundred microliters of POE loaded with 1% wt/wt 5-FU or 5-CU was injected into the subconjunctival space after surgery. Intraocular pressure (IOP) and bleb persistence were monitored for 150 days. RESULTS: In vitro, 5-FU showed a higher antiproliferative effect and a more toxic effect than 5-CU. 5-FU induced cell necrosis, whereas 5-CU induced mostly apoptosis. The apoptosis induced by 5-CU was driven through a non-caspase-dependent pathway involving AIF and LEI/L-DNase II. In vivo, at 34 days after surgery, the mean IOP in the POE/5-CU-treated group was 83% of the baseline level and only 40% in the POE/5-FU-treated group. At 100 days after surgery, IOP was still decreased in the POE/5-CU group when compared with the controls and still inferior to the preoperative value. The mean long-term IOP, with all time points considered, was significantly (P < 0.0001) decreased in the POE/5-CU-treated group (6.0 +/- 2.4 mm Hg) when compared with both control groups, the trabeculectomy alone group (7.6 +/- 2.9 mm Hg), and the POE alone group (7.5 +/- 2.6 mm Hg). Histologic analysis showed evidence of functioning blebs in the POE-5-CU-treated eyes along with a preserved structure of the conjunctiva epithelium. CONCLUSIONS: The slow release of 5-CU from POE has a longstanding effect on the decrease of IOP after glaucoma-filtering surgery in the rabbit eye. Thus, the slow release of POE/5-CU may be beneficial for the prevention of bleb closure in patients who undergo complicated trabeculectomy.

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BACKGROUND: Chemotherapy-induced neutropenia has been associated with prolonged survival selectively in patients on a conventional schedule (combined 5-fluorouracil, leucovorin, and oxaliplatin [FOLFOX2]) but not on a chronomodulated schedule of the same drugs administered at specific circadian times (chronoFLO4). The authors hypothesized that the early occurrence of chemotherapy-induced symptoms correlated with circadian disruption would selectively hinder the efficacy of chronotherapy. METHODS: Fatigue and weight loss (FWL) were considered to be associated with circadian disruption based on previous data. Patients with metastatic colorectal cancer (nâeuro0/00=âeuro0/00543) from an international phase 3 trial comparing FOLFOX2 with chronoFLO4 were categorized into 4 subgroups according to the occurrence of FWL or other clinically relevant toxicities during the initial 2 courses of chemotherapy. Multivariate Cox models were used to assess the role of toxicity on the time to progression (TTP) and overall survival (OS). RESULTS: The proportions of patients in the 4 subgroups were comparable in both treatment arms (Pâeuro0/00=âeuro0/00.77). No toxicity was associated with TTP or OS on FOLFOX2. The median OS on FOLFOX2 ranged from 16.4 (95% confidence limits [CL], 7.2-25.6 months) to 19.8 months (95% CL, 17.7-22.0 months) according to toxicity subgroup (Pâeuro0/00=âeuro0/00.45). Conversely, FWL, but no other toxicity, independently predicted for significantly shorter TTP (Pâeuro0/00<âeuro0/00.0001) and OS (Pâeuro0/00=âeuro0/00.001) on chronoFLO4. The median OS on chronoFLO4 was 13.8 months (95% CL, 10.4-17.2 months) or 21.1 months (95% CL, 19.0-23.1 months) according to presence or absence of chemotherapy-induced FWL, respectively. CONCLUSIONS: Early onset chemotherapy-induced FWL was an independent predictor of poor TTP and OS only on chronotherapy. Dynamic monitoring to detect early chemotherapy-induced circadian disruption could allow the optimization of rapid chronotherapy and concomitant improvements in safety and efficacy.

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This paper proposes new methodologies for evaluating out-of-sample forecastingperformance that are robust to the choice of the estimation window size. The methodologies involve evaluating the predictive ability of forecasting models over a wide rangeof window sizes. We show that the tests proposed in the literature may lack the powerto detect predictive ability and might be subject to data snooping across differentwindow sizes if used repeatedly. An empirical application shows the usefulness of themethodologies for evaluating exchange rate models' forecasting ability.

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The objective of this work was to study the toxicity of pymetrozine and thiamethoxam to the cotton aphid parasitoid Aphelinus gossypii Timberlake and to the whitefly predator Delphastus pusillus (LeConte). Cotton leaves containing mummies of the parasitoid A. gossypii were collected and treated with seven concentrations of both insecticides. Parasitoid emergence was not affected by pymetrozine and ranged from 59.9% to 75.0%, but decreased with the increase of thiamethoxam concentrations ranging from 30.2% to 69.6%. Cotton leaves infested by whitefly and treated with recommended rates of both insecticides were collected three hours, three days and six days after spraying and colonized with larvae and adults of D. pusillus. Predators released on thiamethoxam-treated leaves experienced mortality from 70% to 100%, while those released on pymetrozine-treated leaves showed mortality from 0% to 20%. Topical toxicity from both insecticides was studied on larvae, pupae and adults of D. pusillus. The survival of predator after six days of exposure to 400, 600 and 800 mg/L of pymetrozine a.i. was higher than 69.6%, and to 25, 100 and 200 mg/L of thiamethoxam a.i. was lower than 8.7%. The toxicity data for A. gossypii and D. pusillus characterize the pymetrozine as harmless for both species, and thiamethoxam of low to moderate toxicity for A. gossypii treated mummies, and high toxicity for D. pusillus.

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Diagnosis in allergology is facing novel challenges because of the availability not only of purified or recombinant allergens, but also of multitests such as allergen micro-arrays. These new diagnostic opportunities contribute to a better understanding of crossreactivities between respiratory and food allergens. In comparison to current diagnosis based on whole allergen extracts, this novel generation of specific IgE tests is expected to provide better information on the risk of reaction to allergens as well as on its severity. However these new technologies are expensive, and will have to be carefully analyzed in terms of medical usefulness and public health costs.

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Therapeutic drug monitoring (TDM) and pharmacogenetic tests play a major role in minimising adverse drug reactions and enhancing optimal therapeutic response. The response to medication varies greatly between individuals, according to genetic constitution, age, sex, co-morbidities, environmental factors including diet and lifestyle (e.g. smoking and alcohol intake), and drug-related factors such as pharmacokinetic or pharmacodynamic drug-drug interactions. Most adverse drug reactions are type A reactions, i.e. plasma-level dependent, and represent one of the major causes of hospitalisation, in some cases leading to death. However, they may be avoidable to some extent if pharmacokinetic and pharmacogenetic factors are taken into consideration. This article provides a review of the literature and describes how to apply and interpret TDM and certain pharmacogenetic tests and is illustrated by case reports. An algorithm on the use of TDM and pharmacogenetic tests to help characterise adverse drug reactions is also presented. Although, in the scientific community, differences in drug response are increasingly recognised, there is an urgent need to translate this knowledge into clinical recommendations. Databases on drug-drug interactions and the impact of pharmacogenetic polymorphisms and adverse drug reaction information systems will be helpful to guide clinicians in individualised treatment choices.

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The 2011 International Association of Athletics Federation (IAAF) World Championships took place in Daegu, Korea. For the first time, all athletes were blood tested prior to the competition in order to give a clear signal to the world athletic community of the wish to enter into the era of the Athlete Biological Passport and fight against doping in their sport. The hematological parameters were measured on site. Thus, a mobile-accredited laboratory for blood testing was created in Daegu. Two serum tubes were collected for clinical chemistry and hormonal analyses in order to build the bases of the endocrine and the androgen (steroid) modules of the Athlete Biological Passport in blood. This paper describes some of the main challenges the project faced with regard to the large number of athletes, competing in different disciplines, and the logistic problems that had to be solved for smart implementation of one of the most complex operations organized in the last decade in the fight against doping.

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INTRODUCTION: This trial randomly assessed short-term adjuvant hormonal therapy added to radiotherapy (RT) for intermediate- and high-risk (UICC 1997 cT2a or cT1b-c with high PSA or Gleason score) localised prostate cancer. We report acute toxicity (CTCAE v2) assessed weekly during RT in relation to radiation parameters. PATIENTS AND METHODS: Centres selected the RT dose (70, 74 or 78Gy) and RT technique. Statistical significance is at 0.05. RESULTS: Of 791 patients, 652 received 3D-CRT (70Gy: 195, 74Gy: 376, 78Gy: 81) and 139 received IMRT (74Gy: 28, 78Gy: 111). During RT, grade 3 gastrointestinal (GI) and genitourinary (GU) toxicities were reported by 7 (0.8%) and 50 (6.3%) patients, respectively. No grade 4 was reported. The risk of grade 2 GI toxicity increased significantly with increasing D50%-rectum (p=0.004) and that of grade 2 GU toxicity correlated only to Dmax-bladder (p=0.051). 3D-RT technique, increasing total dose and V95% >400 cc increased D50% and Dmax. One month after RT, only 14 patients (1.8%) reported grade 3 toxicity. AST did not seem to influence the risk of GU or GI acute toxicity. CONCLUSION: RT up to 78Gy was well tolerated. Dmax-bladder and D50%-rectum influenced the risk of grade 2 GU toxicity and GI toxicity, respectively. Both were lower with IMRT but remained high for an irradiated RT volume>400 cc for 3D-RT and for a dose of 78Gy. Hormonal treatment did not influence acute toxicity.