758 research outputs found

    Phase IB study of doxorubicin in combination with the multidrug resistance reversing agent S9788 in advanced colorectal and renal cell cancer.

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    S9788 is a new triazineaminopiperidine derivate capable of reversing multidrug resistance (MDR) in cells resistant to chemotherapeutic agents such as doxorubicin. It does not belong to a known class of MDR revertants, but its action involves the binding of P-glycoprotein. Thirty-eight evaluable patients with advanced colorectal or renal cell cancer were treated with doxorubicin alone (16 patients) followed after disease progression with combination treatment of doxorubicin plus S9788 (12 patients) or upfront with the combination of doxorubicin plus S9788 (22 patients). S9788 was given i.v. as a loading dose of 56 mg m-2 over 30 min followed by doxorubicin given at 50 mg m-2 as a bolus infusion. Thereafter, a 2-h infusion of S9788 was administered at escalating doses ranging from 24 to 120 mg m-2 in subsequent cohorts of 4-10 patients. Pharmacokinetic analysis demonstrated that concentrations of S9788 that are known to reverse MDR in vitro were achieved in patients at non-toxic doses. Compared with treatment with doxorubicin alone, treatment with the combination of doxorubicin and S9788 produced a significant increase in the occurrence of WHO grade 3-4 granulocytopenia. Treatment with S9788 was cardiotoxic as it caused a dose-dependent and reversible increase in corrected QT intervals as well as clinically non-significant arrhythmias on 24- or 48-h Holter recordings. Although clinically relevant cardiac toxicities did not occur, the study was terminated as higher doses of S9788 may increase the risk of severe cardiac arrhythmias. Twenty-nine patients treated with S9788 plus doxorubicin were evaluable for response, and one patient, who progressed after treatment with doxorubicin alone, achieved a partial response. We conclude that S9788 administered at the doses and schedule used in this study results in relevant plasma concentrations in humans and can safely be administered in combination with doxorubicin

    Закономерности распределения аномальных концентраций гелия в палеозойских отложениях Донбасса

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    Підвищені концентрації гелію у вільних і розчинених газах у вугільно-породному масиві Донбасу приурочені до зон зчленування Донбасу з Приазовським і Воронезьким кристалічними масивами і Головної антикліналі. Диз'юнктивні тектонічні порушення глибокого закладення служили, ймовірно, шляхами транзиту гелію від кристалічних порід фундаменту в палеозойські відклади Донбасу, і підвищений вміст гелію може служити індикатором шляхів транзиту газів з глибоких горизонтів Донецького вугільного басейну.Elevated concentrations of helium in free and dissolved gases in coal-rock mass of the Donets Coal Basin are confined to the junction zones of the Donets Coal Basin with the Priazovie and Voronezh crystalline core-areas and Glavnaya (Principal) Anticline. Deep-laid disjunctive dislocations were probably the ways for transit of helium from crystalline basement rocks into Paleozoic deposits of the Basin. Elevated concentrations of helium can also serve as indicators of the ways for transit of gases from deep levels of the Donets Coal Basin

    Gastrointestinal ulceration as a possible side effect of bevacizumab which may herald perforation

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    Chemotherapy plus bevacizumab is currently considered as the standard 1st line treatment of advanced colorectal cancer (ACC). Whereas GI perforation is a known side effect of bevacizumab, the development of GI ulcers has not been reported. We identified 18 patients with ACC who participated in a phase III multicentre trial which included chemotherapy and bevacizumab, who developed a GI ulcer (n = 6), perforation (n = 8) or both (n = 4). The risk of developing a symptomatic GI ulcer or perforation was 1.3% and 1.6%, respectively. Central review of the histology specimens showed ulceration and/or granulation tissue with neovascularisation. The majority (89%) of events developed early during treatment. Given these observations, as well as the relationship between VEGF and mucosal injury healing, we suggest that GI ulcers may occur as a side effect of treatment with bevacizumab and may herald perforation

    Matrix Modulation of the Bioactivation of Estragole by Constituents of Different Alkenylbenzene-containing Herbs and Spices and Physiologically Based Biokinetic Modeling of Possible In Vivo Effects

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    The alkenylbenzene estragole is a constituent of several herbs and spices. It induces hepatomas in rodents at high doses following bioactivation by cytochrome P450s and sulfotransferases (SULTs) giving rise to the ultimate carcinogenic metabolite 1'-sulfooxyestragole which forms DNA adducts. Methanolic extracts from different alkenylbenzene-containing herbs and spices were able to inhibit SULT activity. Flavonoids including quercetin, kaempferol, myricetin, apigenin, and nevadensin were the major constituents responsible for this inhibition with Ki values in the nano to micromolar range. In human HepG2 cells exposed to the proximate carcinogen 1ʹ-hydroxyestragole, the various flavonoids were able to inhibit estragole DNA adduct formation and shift metabolism in favor of glucuronidation which is a detoxification pathway for 1ʹ-hydroxyestragole. In a next step, the kinetics for SULT inhibition were incorporated in physiologically based biokinetic (PBBK) models for estragole in rat and human to predict the effect of co-exposure to estragole and (mixtures of) the different flavonoids on the bioactivation in vivo. The PBBK-model-based predictions indicate that the reduction of estragole bioactivation in rat and human by co-administration of the flavonoids is dependent on whether the intracellular liver concentrations of the flavonoids can reach their Ki values. It is expected that this is most easily achieved for nevadensin which has a Ki value in the nanomolar range and is, due to its methyl ation, more metabolically stable than the other flavonoid

    Experience in implementing harvest strategies in Australia's south-eastern fisheries

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    The Southern and Eastern Scalefish and Shark Fishery (SESSF) is a complex multi-species fishery, with 34 stock units under quota management, for which a harvest strategy framework was developed in 2005. The framework involves the application of a set of tier-based harvest control rules (HCR) designed to provide a precautionary approach to management. The harvest strategy framework has been applied from 2005 to 2007, resulting in substantial reductions in quotas across the fishery. The experience in implementing the framework, both positive and negative, is described, and general lessons are drawn. Key lessons include the importance of formally testing such strategies using management strategy evaluation, the impact of external management drivers on implementation of the approach, the need to define strategies for setting "bycatch quotas" in multi-species fisheries, and the need for flexibility and pragmatism in the early stages of implementing such an approach

    From registration to publication: A study on Dutch academic randomized controlled trials

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    Introduction: Registration of clinical trials has been initiated in order to assess adherence of the reported results to the original trial protocol. This study aimed to investigate the publication rates, timely dissemination of results, and the prevalence of consistency in hypothesis, sample size, and primary endpoint of Dutch investigator-initiated randomized controlled clinical trials (RCTs). Methods: All Dutch investigator-initiated RCTs with a completion date between December 31, 2010, and January 1, 2012, and registered in the Trial Register of The Netherlands database were included. PubMed was searched for the publication of these RCT results until September 2016, and the time to the publication date was calculated. Consistency in hypothesis, sample size, and primary endpoint compared with the registry data were assessed. Results: The search resulted in a total of 168 Dutch investigator-initiated RCTs. In September 2016, the results of 129 (77%) trials had been published, of which 50 (39%) within 2 years after completion of accrual. Consistency in hypothesis with the original protocol was observed in 108 (84%) RCTs; in 71 trials (55%), the planned sample size was reached; and 103 trials (80%) presented the original primary endpoint. Consistency in all three parameters was observe

    Maternal and neonatal bleeding complications in relation to peripartum management in hemophilia carriers:A systematic review

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    Currently, there is no consensus on the optimal management to prevent postpartum hemorrhage (PPH) in hemophilia carriers. We aimed to evaluate peripartum management strategies in relation to maternal and neonatal bleeding outcomes by performing an extensive database search up to August 2020. Seventeen case-reports/series and 11 cohort studies were identified of overall 'poor' quality describing 502 deliveries. The PPH incidence in the individual patient data was 63%; 44% for those women receiving prophylaxis to correct coagulation and 77% for those without (OR 0.23, CI 0.09-0.58) and in cohort data 20.3% (26.8% (11/41) vs. 19.4% (55/284) (OR: 1.53, 95% CI: 0.72-3.24), respectively. Peripartum management strategies mostly consisted of clotting factor concentrates, rarely of desmopressin or plasma. Tranexamic acid appears promising in preventing secondary PPH, but was not used consistently. Neonatal bleeding was described in 6 affected male neonates, mostly after instrumental delivery or emergency CS, but insufficient information was provided to reliably investigate neonatal outcome in relation to management. The high PPH risk seems apparent, at most mildly attenuated by prophylactic treatment. Prospective cohort studies are needed to determine the optimal perinatal management in hemophilia.Thrombosis and Hemostasi

    Phylogenetic and ecological correlates of pollen morphological diversity in a Neotropical rainforest

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    Morphology varies enormously across clades, and the morphology of a trait may reflect ecological function or the retention of ancestral features. We examine the tension between ecological and phylogenetic correlates of morphological diversity through a case study of pollen grains produced by angiosperms in Barro Colorado Island, Panama (BCI). Using a molecular phylogeny of 730 taxa, we demonstrate a statistically significant association between morphological and genetic distance for these plants. However, the relationship is non‐linear, and while close relatives share more morphological features than distant relatives, above a genetic distance of ~ 0.7 increasingly distant relatives are not more divergent in phenotype. The pollen grains of biotically pollinated and abiotically pollinated plants overlap in morphological space, but certain pollen morphotypes and individual morphological traits are unique to these pollination ecologies. Our data show that the pollen grains of biotically pollinated plants are significantly more morphologically diverse than those of abiotically pollinated plants
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