The nature and function of fibroblastoid reticular cells in the hemopoietic stroma

The experimental work of this thesis, described in the appendix papers, is aimed at characterization of the nature and function of fibroblastic reticular cells in the hemopoietic stroma. A number of experimental models was employed to elucidate different aspects of these cells. In the first appendix paper characteristics are described of fibroblastoid colony-forming cells (CFU-F) from murine bone marrow and their in yitro progeny. The data indicate that these fibroblastoid cells differ frorrlm~ phages and endothelial cells, and can be discriminated from fibroblastoid cells from other organs. The second appendix paper describes three monoclonal antibodies that specifically recognize a determinant on non-phagocytic and phagocytic reticular eel ls in the hemopoietic stroma of fetal and adult mice. Reticular stromal cells with this specific determinant(s) are restricted to sites of adulttype hemopoiesis. In the third appendix paper the regulatory capacity of a spleen-derived fibroblastoid cell line on in vitro myelopoiesis is described. This cell line is shown to produce two solUble regulators and one cell-associated activity by which in vitro myelopoiesis is modulated. The fourth appendix paper describes the transplantabil ity of CFU-F after lethal total body irradiation and bone marrow transplantation. Evidence is presented indicating that CFU-F can efficiently lodge in the recipients bone marrow. The fifth appendix paper represents a study of the long-term recovery of CFU-F after lethal total body irradiation and bone marrow transplantation. This recovery is slow and incomplete, independent of graft size and presence of adherent stromal cells in the graft. If present in the graft, donor stromal cells do contribute to the recipients stroma. but they do not influence the total CFU-F recovery. Subsequent treatment with a sublethal dose of endotoxin allows full recovery of the CFU-F population. The sixth appendix paper describes the kinetics of hemopoietic and stromal cells in phenylhydrazine-treated mice. In addition, evidence is presented that under these conditions CFU-F migrate into spleen and bone marrow via the blood stream. In the seventh appendix paper a strong correlation is described between CFU-F numbers and the regenerative capacity of ectopically transplanted stroma in femurs of mice treated with several doses of gamma irradiation

How to optimize communication about animal and animal-free research methods

There is a long-standing debate about experimental non-human animals and animal-free methods in scientific research. Among the various stakeholders involved in the debate are the scientists. During media broadcasts we, animal researchers and animal-free methods researchers, were positioned as ‘opponents’. In this essay we describe our initial rational thoughts and emotions after these events, and how we came together to explore our common ground on animal(−free) experimentation. Realizing that all models have advantages and limitations, our common ground lies in the principles of good scientific research and responsible experimentation. Our communication emanating from the broadcasts has been instrumental in improving communication on animal(−free) experimentation issues by teaming up. We strongly believe that this is essential for making well-informed decisions for the methods we are using now and will be using in the future

Мінливість дуже сильних дощів і сильних злив в Україні

Розглянуто міжрічну мінливість кількості випадків стихійних гідрометеорологічних явищ (СГЯ), а саме: дуже сильних дощів і сильних злив – в Україні та її регіонах у другій половині ХХ – на початку ХХІ ст. Використавши методи сезонної декомпозиції, встановлено тенденцію динаміки цих рядів протягом досліджуваного періоду. Шляхом автокореляційного та спектрального аналізів визначено циклічні компоненти у структурі рядів річної кількості випадків СГЯ та їх особливості в періоди, коли спостерігали тенденцію до зменшення і збільшення інтенсивності цих явищ.Рассмотрена межгодовая изменчивость количества случаев очень сильных дождей и сильных ливней в Украине и ее регионах во второй половине ХХ - в начале ХХІ в. Установлена тенденция динамики этих рядов на протяжении исследуемого периода. Определены циклические компоненты в структуре рядов годового количества случаев стихийных осадков (СГЯ) и их особенности в периоды, когда наблюдали тенденцию к уменьшению и увеличению интенсивности этих явлений

Адаптація в українській термінології іншомовних лексем на позначення засобів розміщення туристів

Розглянуто шляхи та причини запозичення іншомовної лексики на позначення засобів розміщення туристів, подано значення окремих запозичених лексем.The article studies the ways and reasons for lexical units denoting tourist accommodation borrowing. The meanings of some borrowed terms are given

A transcriptomic approach for evaluating the relative potency and mechanism of action of azoles in the rat Whole Embryo Culture.

We evaluated the effect of six azoles on embryonic development in the rat whole embryo culture (WEC). Using the total morphological scoring system (TMS), we calculated the ID10concentration (effective dose for 10% decrease in TMS). For evaluating gene specific responses, we combined previously and newly collected transcriptomics data of rat WEC exposed to a total of twelve azoles at their ID10for 4h. Results revealed shared expressions responses in genes involved in the retinoic acid (RA) and sterol biosynthesis pathways, which are respectively representatives of developmental toxicity and targeted fungicidal action of the azoles. Azoles with more pronounced effects on the regulation of RA-associated genes were generally characterized as more potent embryotoxicants. Overall, compounds with strong sterol biosynthesis related responses and low RA related responses were considered as more favourable candidates, as they specifically regulated genes related to a desired target response. Among the identified sterol associated genes, we detected that methylsterol monooxygenase 1 (Msmo1) was more sensitively induced compared to Cyp51, a classical biomarker of this pathway. Therefore, we suggest that Msmo1 could be a better biomarker for screening the fungicidal value of azoles. In summary, we conclude that the embryonic regulation of RA and sterol metabolic pathways could be indicators for ranking azoles as embryotoxicants and determining their drug efficacy

Інноваційна активність підприємств України: технологічний аспект

Hazard assessment of chemicals and pharmaceuticals is increasingly gaining from knowledge about molecular mechanisms of toxic action acquired in dedicated in vitro assays. We have developed an efficient human embryonic stem cell neural differentiation test (hESTn) that allows the study of the molecular interaction of compounds with the neural differentiation process. Within the 11-day differentiation protocol of the assay, embryonic stem cells lost their pluripotency, evidenced by the reduced expression of stem cell markers Pou5F1 and Nanog. Moreover, stem cells differentiated into neural cells, with morphologically visible neural structures together with increased expression of neural differentiation-related genes such as beta III-tubulin, Map2, Neurogin1, Mapt and Reelin. Valproic acid (VPA) and carbamazepine (CBZ) exposure during hESTn differentiation led to concentration-dependent reduced expression of beta III-tubulin, Neurogin1 and Reelin. In parallel VPA caused an increased gene expression of Map2 and Mapt which is possibly related to the neural protective effect of VPA. These findings illustrate the added value of gene expression analysis for detecting compound specific effects in hESTn. Our findings were in line with and could explain effects observed in animal studies. This study demonstrates the potential of this assay protocol for mechanistic analysis of specific compound-induced inhibition of human neural cell differentiation. (c) 2014 Elsevier Ltd. All rights reserved

Диалог культур – парадигма современного социокультурного процесса

To improve the predictability of the zebrafish embryotoxicity test (ZET) for developmental (neuro)toxicity screening, we used a multiple-endpoints strategy, including morphology, motor activity (MA), histopathology and kinetics. The model compounds used were antiepileptic drugs (AEDs): valproic acid (VPA), carbamazepine (CBZ), ethosuximide (ETH) and levetiracetam (LEV). For VPA, histopathology was the most sensitive parameter, showing effects already at 60. μM. For CBZ, morphology and MA were the most sensitive parameters, showing effects at 180. μM. For ETH, all endpoints showed similar sensitivity (6.6. mM), whereas MA was the most sensitive parameter for LEV (40. mM). Inclusion of kinetics did not alter the absolute ranking of the compounds, but the relative potency was changed considerably. Taking all together, this demo-case study showed that inclusion of multiple-endpoints in ZET may increase the sensitivity of the assay, contribute to the elucidation of the mode of toxic action and to a better definition of the applicability domain of ZET

Pluripotent stem cell assays: Modalities and applications for predictive developmental toxicity

This manuscript provides a review focused on embryonic stem cell-based models and their place within the landscape of alternative developmental toxicity assays. Against the background of the principles of developmental toxicology, the wide diversity of alternative methods using pluripotent stem cells developed in this area over the past half century is reviewed. In order to provide an overview of available models, a systematic scoping review was conducted following a published protocol with inclusion criteria, which were applied to select the assays. Critical aspects including biological domain, readout endpoint, availability of standardized protocols, chemical domain, reproducibility and predictive power of each assay are described in detail, in order to review the applicability and limitations of the platform in general and progress moving forward to implementation. The horizon of innovative routes of promoting regulatory implementation of alternative methods is scanned, and recommendations for further work are given

Next-generation text-mining mediated generation of chemical response-specific gene sets for interpretation of gene expression data

Background: Availability of chemical response-specific lists of genes (gene sets) for pharmacological and/or toxic effect prediction for compounds is limited. We hypothesize that more gene sets can be created by next-generation text mining (next-gen TM), and that these can be used with gene set analysis (GSA) methods for chemical treatment identification, for pharmacological mechanism elucidation, and for comparing compound toxicity profiles. Methods. We created 30,211 chemical response-specific gene sets for human and mouse by next-gen TM, and derived 1,189 (human) and 588 (mouse) gene sets from the Comparative Toxicogenomics Database (CTD). We tested for significant differential expression (SDE) (false discovery rate -corrected p-values < 0.05) of the next-gen TM-derived gene sets and the CTD-derived gene sets in gene expression (GE) data sets of five chemicals (from experimental models). We tested for SDE of gene sets for six fibrates in a peroxisome proliferator-activated receptor alpha (PPARA) knock-out GE dataset and compared to results from the Connectivity Map. We tested for SDE of 319 next-gen TM-derived gene sets for environmental toxicants in three GE data sets of triazoles, and tested for SDE of 442 gene sets associated with embryonic structures. We compared the gene sets to triazole effects seen in the Whole Embryo Culture (WEC), and used principal component analysis (PCA) to discriminate triazoles from other chemicals. Results: Next-gen TM-derived gene sets matching the chemical treatment were significantly altered in three GE data sets, and the corresponding CTD-derived gene sets were significantly altered in five GE data sets. Six next-gen TM-derived and four CTD-derived fibrate gene sets were significantly altered in the PPARA knock-out GE dataset. None of the fibrate signatures in cMap scored significant against the PPARA GE signature. 33 environmental toxicant gene sets were significantly altered in the triazole GE data sets. 21 of these toxicants had a similar toxicity pattern as the triazoles. We confirmed embryotoxic effects, and discriminated triazoles from other chemicals. Conclusions: Gene set analysis with next-gen TM-derived chemical response-specific gene sets is a scalable method for identifying similarities in gene responses to other chemicals, from which one may infer potential mode of action and/or toxic effect