51 research outputs found

    A phase II study of the histone deacetylase inhibitor vorinostat combined with tamoxifen for the treatment of patients with hormone therapy-resistant breast cancer

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    BackgroundHistone deacetylases (HDACs) are crucial components of the oestrogen receptor (ER) transcriptional complex. Preclinically, HDAC inhibitors can reverse tamoxifen/aromatase inhibitor resistance in hormone receptor-positive breast cancer. This concept was examined in a phase II combination trial with correlative end points.MethodsPatients with ER-positive metastatic breast cancer progressing on endocrine therapy were treated with 400 mg of vorinostat daily for 3 of 4 weeks and 20 mg tamoxifen daily, continuously. Histone acetylation and HDAC2 expression in peripheral blood mononuclear cells were also evaluated.ResultsIn all, 43 patients (median age 56 years (31-71)) were treated, 25 (58%) received prior adjuvant tamoxifen, 29 (67%) failed one prior chemotherapy regimen, 42 (98%) progressed after one, and 23 (54%) after two aromatase inhibitors. The objective response rate by Response Evaluation Criteria in Solid Tumours criteria was 19% and the clinical benefit rate (response or stable disease >24 weeks) was 40%. The median response duration was 10.3 months (confidence interval: 8.1-12.4). Histone hyperacetylation and higher baseline HDAC2 levels correlated with response.ConclusionThe combination of vorinostat and tamoxifen is well tolerated and exhibits encouraging activity in reversing hormone resistance. Correlative studies suggest that HDAC2 expression is a predictive marker and histone hyperacetylation is a useful pharmacodynamic marker for the efficacy of this combination

    Medicinal and ethnoveterinary remedies of hunters in Trinidad

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    BACKGROUND: Ethnomedicines are used by hunters for themselves and their hunting dogs in Trinidad. Plants are used for snakebites, scorpion stings, for injuries and mange of dogs and to facilitate hunting success. RESULTS: Plants used include Piper hispidum, Pithecelobium unguis-cati, Bauhinia excisa, Bauhinia cumanensis, Cecropia peltata, Aframomum melegueta, Aristolochia rugosa, Aristolochia trilobata, Jatropha curcas, Jatropha gossypifolia, Nicotiana tabacum, Vernonia scorpioides, Petiveria alliacea, Renealmia alpinia, Justicia secunda, Phyllanthus urinaria,Phyllanthus niruri,Momordica charantia, Xiphidium caeruleum, Ottonia ovata, Lepianthes peltata, Capsicum frutescens, Costus scaber, Dendropanax arboreus, Siparuma guianensis, Syngonium podophyllum, Monstera dubia, Solanum species, Eclipta prostrata, Spiranthes acaulis, Croton gossypifolius, Barleria lupulina, Cola nitida, Acrocomia ierensis (tentative ID). CONCLUSION: Plant use is based on odour, and plant morphological characteristics and is embedded in a complex cultural context based on indigenous Amerindian beliefs. It is suggested that the medicinal plants exerted a physiological action on the hunter or his dog. Some of the plants mentioned contain chemicals that may explain the ethnomedicinal and ethnoveterinary use. For instance some of the plants influence the immune system or are effective against internal and external parasites. Plant baths may contribute to the health and well being of the hunting dogs

    Epigenetic polypharmacology: from combination therapy to multitargeted drugs

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    The modern drug discovery process has largely focused its attention in the so-called magic bullets, single chemical entities that exhibit high selectivity and potency for a particular target. This approach was based on the assumption that the deregulation of a protein was causally linked to a disease state, and the pharmacological intervention through inhibition of the deregulated target was able to restore normal cell function. However, the use of cocktails or multicomponent drugs to address several targets simultaneously is also popular to treat multifactorial diseases such as cancer and neurological disorders. We review the state of the art with such combinations that have an epigenetic target as one of their mechanisms of action. Epigenetic drug discovery is a rapidly advancing field, and drugs targeting epigenetic enzymes are in the clinic for the treatment of hematological cancers. Approved and experimental epigenetic drugs are undergoing clinical trials in combination with other therapeutic agents via fused or linked pharmacophores in order to benefit from synergistic effects of polypharmacology. In addition, ligands are being discovered which, as single chemical entities, are able to modulate multiple epigenetic targets simultaneously (multitarget epigenetic drugs). These multiple ligands should in principle have a lower risk of drug-drug interactions and drug resistance compared to cocktails or multicomponent drugs. This new generation may rival the so-called magic bullets in the treatment of diseases that arise as a consequence of the deregulation of multiple signaling pathways provided the challenge of optimization of the activities shown by the pharmacophores with the different targets is addressed

    Methodology of calculation of construction and hydrodynamic parameters of a foam layer apparatus for mass-transfer processes

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    Промислова реалізація методу стабілізації газорідинного шару дозволяє значно розширити галузь застосування пінних апаратів і відкриває нові можливості інтенсифікації технологічних процесів з одночасним створенням маловідходних технологій. У статті встановлені основні параметри, що впливають на гідродинаміку пінних апаратів, розглянуті основні конструкції та режими роботи пінних апаратів. Виявлено зв'язок гідродинамічних параметрів. Розглянуто гідродинамічні закономірності пінного шару. Вказані фактори, що впливають на процес масообміну, як в газовій, так і в рідкій фазах. Проведений аналіз ряду досліджень показав, що перспективним напрямком інтенсифікації процесу масообміну є розробка апаратів з трифазним псевдозрідженим шаром зрошуваної насадки складних форм із сітчастих матеріалів. Отже, необхідне проведення спеціальних досліджень гідродинамічних режимів роботи апарату з сітчастою насадкою і визначенням параметрів, що впливають на швидкість переходу насадки з одного режиму в інший.Industrial implementation of the stabilization method of the gas-liquid layer can significantly expand the field of use of foaming apparatus and opens up new opportunities for intensifying technological processes with the simultaneous creation of low-waste technologies. The article establishes the basic parameters influencing the hydrodynamics of foam apparatus, considers the basic constructions and operating modes of foam apparatus. The connection of hydrodynamic parameters is revealed. The hydrodynamic laws of the foam layer are considered. The indicated factors affecting the process of mass transfer, both in the gas and in the liquid phases. The conducted analysis of a number of studies showed that the perspective direction of intensification of the mass transfer process is the development of apparatuses with a three-phase fluidized bed of an irrigated nozzle of complex forms with mesh materials

    A many-analysts approach to the relation between religiosity and well-being

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    The relation between religiosity and well-being is one of the most researched topics in the psychology of religion, yet the directionality and robustness of the effect remains debated. Here, we adopted a many-analysts approach to assess the robustness of this relation based on a new cross-cultural dataset (N=10,535 participants from 24 countries). We recruited 120 analysis teams to investigate (1) whether religious people self-report higher well-being, and (2) whether the relation between religiosity and self-reported well-being depends on perceived cultural norms of religion (i.e., whether it is considered normal and desirable to be religious in a given country). In a two-stage procedure, the teams first created an analysis plan and then executed their planned analysis on the data. For the first research question, all but 3 teams reported positive effect sizes with credible/confidence intervals excluding zero (median reported β=0.120). For the second research question, this was the case for 65% of the teams (median reported β=0.039). While most teams applied (multilevel) linear regression models, there was considerable variability in the choice of items used to construct the independent variables, the dependent variable, and the included covariates

    Tick toxinology : isolation and characterisation of the toxin from the Australian paralysis tick, Ixodes holocyclus

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    University of Technology, Sydney. Faculty of Science.Several species of ticks have been reported to secrete neurotoxins which can be fatal to mammals, including man. Envenomation by the Australian paralysis tick, I. holocyclus, is a considerable veterinary problem affecting tens of thousands of domestic and native animals each year. Envenomation is characterised by a progressive ascending flaccid paralysis and is due to a neurotoxin present in the salivary secretions of the tick. Purification of the neurotoxic component has been largely unsuccessful mainly due to the insensitivity of the biological assay, the minute quantities present and the reported labile nature of the neurotoxin. This dissertation describes the identification, final purification, partial characterisation and preliminary structural characteristics of the neurotoxins from I. holocyclus. The neurotoxins were identified as having a molecular weight of 5 kD by SDS-PAGE using an innovative technique involving adsorption to synaptosomes. The identification subsequently enabled the final purification of three closely related neurotoxins. The neurotoxins were purified from extracts of engorged adult female I. holocyclus by a series of conventional chromatography techniques (heparin Sepharose, DEAE Affi-gel blue, Alkyl Sepharose) followed by C4 and CB reverse phase HPLC. Purity was demonstrated by Tricine-SDS-PAGE and biological activity confirmed by injection into neonatal mice. Total amino acid analysis of the three neurotoxins showed that the neurotoxins were essentially identical. This was latter confirmed by a non-neutralising monoclonal antibody which was capable of recognising a common epitope shared by all three neurotoxins. Amino acid sequence of the neurotoxins was restricted to peptides generated by proteolytic digestion with trypsin as direct N-terminal sequencing revealed an amino-terminal blockage. An accurate molecular weight of 5,640 (HT-II) and 5,460 (HT-I) Daltons has been determined by mass spectrometry for two of the neurotoxins. The small size is comparable to neurotoxins isolated from other arachnids (spiders and scorpions). However, comparisons of the peptide amino acid sequences derived from the proteolytic digestion of HT-II with known protein sequences failed to display any significant homologies. cDNA libraries were produced from poly(A⁺) mRNA isolated from unengorged I. holocyclus ticks. The libraries were characterised and found to be well-represented with tick-derived cDNA sequences. PCR primers and oligonucleotide probes were designed from the partial amino acid sequence obtained for HT-II and used to screen the cDNA libraries. After extensively screening the libraries, no positive clones were obtained. Northern hybridisation analysis of total RNA prepared from unengorged and engorged ticks with the oligonucleotide probe RHT produced a band of the expected size (220 bps), only with total RNA prepared from engorged ticks. This indicated the original cDNA libraries prepared from unengorged ticks were unlikely to contain the gene of interest. PCR based strategies were unable to isolate neurotoxin gene(s) from mRNA prepared from engorged ticks
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