Macroscopic “carbonaceous” fossils such as Grypania, Katnia, Chuaria, and Tawuia play a critical role in our understanding of biological evolution in the Precambrian and their environmental implications. Unfortunately, understanding of these fossils remains limited by their relative simplicity of form, mode of preservation, and broad taphonomic variability. As a result, debate continues as to even the fundamental taxonomic affinity of the organisms. Megascopic coiled forms (i.e. Grypania and Katnia), for instance, have been interpreted as trace fossils, multicellular algae, prokaryotic filaments, macroscopic bacteria, cyanobacteria, or a transitional form from macroscopic to megascopic bacterial life. Similarly, Chuaria and Tawuia have been interpreted as compressed prokaryotic colonies, algae or algal reproductive stages, and multicellular plant material. Accessibility of new material and increasingly sophisticated means of analysis warrant a new look at these ancient fossils. Understanding the biological affinity of Grypania, in particular, is critical because current opinion is split as to whether these megascopic structures are more likely represent either multicellular bacteria or multicellular algae. Confirmation of either a bacterial or algal affinity would strongly influence fundamental understanding of biospheric evolution, particularly in terms of ocean oxygenation and the availability of bioessential trace metals. Although estimates for the degree of oxygenation required for a Grypania-like multicellular algae are only about 10 % present atmospheric levels (PAL), this estimate is still substantially higher than estimates based on geochemical data suggesting that oxygen levels may not have reached 10% PAL until the latter Neoproterozoic. It has been hypothesized that protracted oxygen of the Proterozoic biosphere may have played a critical role in the availability of redox-sensitive nutrients necessary for bacterial nitrogen fixation and the limiting of eukaryotic evolution. Within this context, our understanding of the taxonomic affinity of Grypania may profoundly affect our understanding of Earth’s biospheric evolution. This thesis provides morphological and geochemical analyses of Grypania spiralis from more than 100 newly collected specimens from the Belt Supergroup for comparison to previously collected specimens from all other known Grypania-bearing localities. Data is used to explore questions regarding the morphology, structural complexity, mode of preservation, and chemistry of fossil material, and to hypothesize on the taxonomic affinity of Grypania spiralis and its implications for biospheric evolution.

published_or_final_version / abstract / toc / Zoology / Master / Master of Philosophy

Les maladies tropicales, notamment les parasitoses, constituent un problème de santé publique majeur dans les pays les moins avancés. Les rares traitements disponibles deviennent de moins en moins efficaces du fait de phénomènes de résistances, justifiant la recherche de nouveaux agents thérapeutiques possédant des mécanismes d'actions innovants. Les molécules électrophiles ayant dans leur structure un motif accepteur de Michael (AM) sont capables d'inhiber certains systèmes enzymatiques indispensables à la survie des parasites mais aussi de moduler la réponse immunitaire de l'hôte parasité, leur conférant ainsi des propriétés antiparasitaires. Dans ce contexte, ce travail de recherche a porté sur l'isolement de lactones sesquiterpéniques à partir de l'espèce Pseudelephantopus spiralis (Less.) Cronquist. Ces métabolites secondaires comportent dans leur structure des motifs AM et sont biologiquement très actifs. L'espèce P. spiralis a été choisie sur la base de critères chimiotaxonomiques, ethnopharmacologiques et suite au criblage de l'extrait éthanolique de ses feuilles sur Leishmania amazonensis (CI50=0,9 µg/mL). L'étude phytochimique de P. spiralis a conduit à l'isolement de 7 lactones sesquiterpéniques de type hirsutinolides à partir des extraits éther de pétrole, éthanolique et aqueux des parties aériennes de la plante. Ces molécules ont été identifiées par des techniques de spectroscopie (RMN, MS) puis testées in vitro sur deux modèles parasitaires : L. infantum et Plasmodium falciparum. Parallèlement, leur cytotoxicité a été évaluée sur deux lignées cellulaires saines afin de déterminer leurs indices de sélectivité. Deux de ces molécules, le diacetylpiptocarphol et la piptocarphine A, ont présenté une bonne activité sur les deux parasites mais ont manqué de sélectivité (IS<1). Ces deux composés ont également été testés pour leur effet sur la stimulation des monocytes/macrophages. Plus particulièrement, la promotion de l'expression de récepteur scavenger CD36 à la surface des macrophages et de l'enzyme cytoprotectrice Hème Oxygénase HO-1 a été évaluée. Le récepteur CD36 est impliqué dans la reconnaissance et la phagocytose non-opsonique des érythrocytes parasités par les Plasmodia et l'induction de HO-1 semble réduire la sévérité de trypanosomiases et paludismes chez modèles murins. Une étude par spectrométrie de masse haute résolution et fragmentations séquentielles réalisée au Louvain Drug Research Institute (Bruxelles) a permis d'étudier la fragmentation des hirsutinolides isolés afin de développer une méthode de détection par UHPLC-DAD-MS/MS de ces composés au sein d'un extrait. Cette méthode a été appliquée à la déréplication d'extraits de P. spiralis. / Tropical diseases, including parasitosis, are major public health problems in developing countries. The few existing treatments are becoming less effective due to the emergence of pharmacoresistances, justifying the search for new therapeutic agents with innovative mechanisms. Electrophilic compounds displaying in their structure a Michael acceptor moiety (MA) are able to inhibit some of the parasites enzymatic systems, essential for their survival, and are potent modulators of the parasited host immune response. This confers them antiparasitic properties. In this context, this work presents the isolation of sesquiterpene lactones from the species Pseudelephantopus spiralis (Less.) Cronquist. These secondary metabolites display MA moieties in their structure and are potent biological active compounds. The species Pseudelephantopus spiralis (Less.) Cronquist was chosen on the basis of chimiotaxonomical and ethnopharmacological criteria and due to the very good antileishmanial activity of the ethanolic extract of the aerial parts on Leishmania amazonensis (IC50=0.9 µg/mL). The phytochemical study of P. spiralis led to the isolation of 7 sesquiterpene lactones exhibiting a hirsutinolide-type core in their structure, isolated from petroleum ether, ethanolic and aqueous extracts of plant's aerial parts. The isolated compounds were identified by spectroscopic techniques (NMR, MS) and tested in vitro for their anti-parasitic potential against two models: L. infantum and Plasmodium falciparum. In parallel their cytotoxicity on two healthy cell lines was evaluated in order to determine their selectivity indexes. Two of the isolated compounds, diacetylpiptocarphol and piptocarphin A, displayed a good activity on both parasite models but lacked of selectivity (SI<1). These two compounds were also tested for their effects on the macrophages/monocytes stimulation. Especially the promotion of the expression of the scavenger receptor CD36 on macrophages surface and the cytoprotective Heme Oxygenase enzyme HO-1 was evaluated. CD36 receptor is involved in the recognition and the nonopsonic phagocytosis of Plasmodia-parasitized erythrocytes and HO-1 induction reduces the severity of trypanosomiasis and malaria in murine models. An analytical study using high resolution mass spectrometry and sequential fragmentation was led at the Louvain Drug Research Institute (Brussels) in order to study the fragmentation of isolated hirsutinolides and to develop a method for their detection by UHPLC-DAD-MS/MS in complex extracts. This was applied to the dereplication of P. spiralis extracts.

No description available.

No description available.

The intracellular parasite Trichinella is a genus in phylum Nematoda that contains six named species including Trichinella spiralis and Trichinella pseudospiralis. These parasites infect a large variety of wild and domestic animals, human beings and a few species of birds. The parasitic strategies and the pathological effects on the host between trichinella spiralis and Trichinella pseudospiralis are quite different. The purpose of this study is to gain an understanding of the physiological, immunological and pathological differences between these two species of Trichinella using infections in the mouse as a model. In the course of this research I have attempted to answer the following questions: A) Is cortisol a factor in the differences of the host response to Trichinella spiralis or Trichinella pseudospiralis? B) Are there differences in leukocyte response in the peripheral blood of Trichinella infected mice? C) Are there differences in the up-regulation or down-regulation of cell surface molecules on leukocytes in the spleens of Trichinella infected mice? D) Is there a difference in the degree of muscle damage (as measured by creatine phosphokinase) when infections by the two species of Trichinella are compared? E) Are there differences in angiogenesis and collagen deposition in Trichinella infected mice and are these differences related to cortisol? F) Is nitric oxide a component in parasite killing and are there differences in nitric oxide production in host mice when the two species of Trichinella are compared? My research has shown that there are significant differences in the parasitic strategies and pathological consequences in mice infected with one or the other of the two species of Trichinella. The two species appear to generate different immune and inflammatory responses from the host. Trichinella pseudospiralis is much less damaging to the host, generates a very different peripheral blood response, stimulates the production of substantially greater levels of serum cortisol, generates a significantly different profile in cytokine production presents a very different cell surface antigen profile and does not produce a collagen nurse cell or generate an angiogenic response when compared to T spiralis. In addition, I have shown a role for nitric oxide in parasite killing and a role for serum cortisol in larval survival. I have also shown that cortisol has no role in either collagen deposition or the angiogenic response in Balb/c mice under the experimental conditions detailed here.

Ph.d.-afhandling. University of Helsinki, 2006. / Også elektronisk adgang via Internettet.

Made available in DSpace on 2014-06-11T19:31:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-05-20Bitstream added on 2014-06-13T19:20:29Z : No. of bitstreams: 1 araujo_mgf_dr_arafcf.pdf: 2084466 bytes, checksum: cbbeaab6200eb613c54158e1494c0dfd (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A família Eriocaulaceae apresenta cerca de 1.200 espécies e 11 gêneros, com distribuição pantropical. Suas espécies são conhecidas popularmente como „sempre viva‟. Leiothrix spiralis Ruhland e Syngonanthus nitens (Bong) Ruhland são espécies de Eriocaulaceae, estudos químicos tem mostrado predominantemente a presença de xantonas e flavonas, principalmente O-glicosídeos e C-glicosídeos derivados da luteolina. Propriedades etnofarmacológicas de Eriocaulaceae são pouco conhecidas. Por esta razão, foi avaliado o potencial biológico dos extratos e compostos isolados das espécies L. spiralis e S. nitens. Os extratos metanólicos de escapos, capítulos e folhas destas espécies e os compostos fenólicos isolados do extrato metanólico de folhas de L. spiralis mostraram significativa atividade antimicrobiana contra bactérias Gram-positivas e Gram-negativas e leveduras, a capacidade antioxidante pelo ensaio de redução do ABTS●+ pode ser observada. Os extratos foram avaliados quanto à capacidade de inibir a formação de hifas de C. albicans, sendo verificado que o extrato de escapos de S. nitens foi capaz de inibir a fase de transição para a forma filamentosa. As atividades citotóxica e hemolítica dos extratos foram investigadas e o extrato metanólico de folhas de L. spiralis apresentou ação citotóxica sobre as células HeLa. O extrato de escapos de S. nitens foi incorporado a um creme vaginal e avaliada a atividade antifúngica e mutagênica em um modelo animal de candidíase vaginal. Os resultados mostraram que o tratamento com este produto foi eficaz neste modelo animal, erradicando a carga fúngica vaginal de ratas infectadas após 8 dias de tratamento. A atividade mutagênica foi avaliada pelo teste do micronúcleo, em tratamento agudo e subagudo, e o produto não apresentou mutagenicidade nessas condições. O presente estudo sugere que estas espécies podem ser uma fonte promissora para aplicação como antifúngico / Eriocaulaceae is a pantropical family, comprising around 1200 species in 11 genera. Their species are popularly known as „sempre viva‟. Leiothrix spiralis Ruhland and Syngonanthus nitens (Bong.) Ruhland are two species of Eriocaulaceae, and chemical studies of these species showed predominantly flavones, mainly O-glucosides and C-glucosides derivatives of luteolin. The ethnopharmacological properties of Eriocaulaceae are little known. For this reason we evaluate the biological potential of extracts and isolated compounds from L. spiralis and S. nitens. The methanolic extracts from capitula and flower heads from this species and the phenolics isolated from the methanolic extract of leaves of L. spiralis showed significantly antimicrobial activity against Gram-positive and Gram-negative organisms and yeasts, and the antioxidant capacity by the ABTS●+ reduction assay could be observed. The extracts were evaluated as the ability to inhibit the hyphal formation on C. albicans and the extract of flower heads of S. nitens was able to inhibit the transition stage from budding to hyphal growth. The cytotoxic and hemolytic activities of the extracts were investigated and the extract of leaves of L. spiralis showed cytotoxic action on HeLa cells. A vaginal cream containing the methanolic extract of scapes from S. nitens was tested as antifungal and mutagenic in a vaginal candidiasis animal model. The results showed that treatment with this product was very effective in this animal model, and was able eradicate the vaginal fungal burden of infected rats after 8 days on treatment. The in vivo mutagenic activity of the vaginal cream was assessed by the micronucleus assay, in acute and subacute treatment, and it was not mutagenic in this conditions. The present study suggests that these Eriocaulaceae species could be a promising source of compounds to produce antifungal phytomedicines

Submitted by REBECA PREVIATE MEDINA null (rebecapm_2@hotmail.com) on 2016-07-12T01:22:08Z No. of bitstreams: 1 tese completa final.pdf: 17929997 bytes, checksum: 2ca69cdbb8845123f617feff1388a3eb (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-07-12T20:30:01Z (GMT) No. of bitstreams: 1 medina_rp_dr_araiq_par.pdf: 1819041 bytes, checksum: 6a9b96f8294269d0ff2fc5f05f6dd74b (MD5) / Made available in DSpace on 2016-07-12T20:30:01Z (GMT). No. of bitstreams: 1 medina_rp_dr_araiq_par.pdf: 1819041 bytes, checksum: 6a9b96f8294269d0ff2fc5f05f6dd74b (MD5) Previous issue date: 2016-06-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os Produtos Naturais desempenham um papel dominante na descoberta e desenvolvimento de novos fármacos para o tratamento de diversas doenças. Com isso, a busca por novas fontes de substâncias bioativas tem se intensificado, com destaque para estudos realizados com organismos e micro-organismos marinhos. As algas vermelhas marinhas (Rhodophyta) são as principais produtoras de metabólitos secundários biologicamente ativos dentre as algas e produzem principalmente substâncias halogenadas. Dentre os micro-organismos, podemos destacar os fungos endofíticos de algas marinhas, pois apresentam alta diversidade de espécies e diversidade estrutural dos metabólitos secundários, os quais têm mostrado potencial antitumoral, antimicrobiano e antifúngico. Sendo assim, este trabalho teve como objetivo explorar o potencial das algas vermelhas Asparagopsis taxiformis (estágio Falkenbergia) e Pyropia spiralis, bem como de seus fungos endofíticos, como fontes de substâncias bioativas. O estudo de A. taxiformis e de P. spiralis levou à identificação de dezesseis substâncias por CG-EM, como os ácidos eicosapentaenóico e araquidônico, além de nucleosídeos, como a uridina e a timidina, obtidos de A. taxiformis, e a uridina e a inosina, obtidas de P. spiralis. Os extratos brutos e frações das algas estudadas foram avaliados frente ao fungo fitopatogênico Cladosporium sphaerospermum, frente à enzima acetilcolinesterase e frente a linhagens tumorais de carcinoma de ovário (OVCAR-8), adenocarcinoma de cólon humano (HCT-116) e glioblastoma - humano (SF-295), sendo que os mesmos não apresentaram atividades antifúngica e anticolinesterásica significativas e apenas as frações hexânicas e butanólicas de ambas as algas apresentaram atividade citotóxica moderada frente à linhagem SF-295. Em relação ao estudo dos micro-organismos associados às algas, foi possível isolar sete linhagens de fungos endofíticos da alga A. taxiformis e três linhagens de P. spiralis, que foram cultivadas em meio de batata e dextrose (MBD) preparado com água do mar ou água ultra pura. Após o período de incubação, foram obtidos os extratos brutos em acetato de etila, que foram avaliados quanto ao perfil químico por CLAE e RMN, e perfil biológico por meio dos bioensaios in vitro. Após a prospecção inicial, Nemania bipapillata (AT-05), Sarocladium strictum (PS-01), Annulohypoxylon stygium (AT-03) e Hypoxylon sp. (AT-06) foram selecionados para investigação. O estudo de N. bipapillata, cultivado em água do mar e MBD, levou ao isolamento da dicetopiperazina ciclo(Pro-Tir), tirosol e das isocumarinas, (3R)-5-hidroximetil-meleína e (3R)-5-carbóxi-meleína. Ao cultivar essa linhagem fúngica em água ultra pura e MDB, foram isolados dois norsesquiterpenos e três sesquiterpenos do tipo botriano inéditos na literatura e um conhecido, 4β-acetoxi-9β,10β,15α-triidroxiprobotridial. A análise do extrato bruto de S. strictum, cultivado em água ultra pura e MDB, levou à identificação em mistura de duas dicetopiperazinas e ao isolamento da isoflavona daidzeína e de seis ftalatos naturais, dos quais dois ainda não foram descritos na literatura e nem sintetizados. A. stygium e Hypoxylon sp. foram cultivados em água do mar e MDB, sendo que A. stygium forneceu o pirogalol, que apresentou atividade contra Escherichia coli e Staphylococcus aureus resistente a meticilina, além do tirosol e (˗)-(3R,4R)-3,4,5-triidróxi-tetralona, enquanto Hypoxylon sp. forneceu (3R)-scytalona, (3R,4R)-4-hidróxi-scytalona e daidzeína. Portanto, esses resultados ressaltam a importância da investigação dos organismos marinhos, bem como de seus micro-organismos associados, e contribuem para o conhecimento da quimiodiversidade de organismos de origem marinha da costa brasileira, ainda sub-explorada do ponto de vista químico. / Natural Products have a major role in the discovery and development of new drugs used for diseases treatments. Thus, the search for new sources of bioactive compounds has been intensified and studies have increasingly focused on marine organisms and microorganisms. Marine red algae (Rhodophyta) are the major producers of biologically active secondary metabolites among algae, and biosynthesize mainly halogenated compounds. Among microorganisms, we highlight endophytic fungi from marine algae, as they present marked species diversity as well as structural diversity of secondary metabolites. Such metabolites have shown interesting potential as antitumor, antimicrobial and antifungal agents. Therefore, this project aimed to explore the potential of red algae Asparagopsis taxiformis (Falkenbergia stage) and Pyropia spiralis and their endophytic fungi, as novel sources of bioactive compounds. The study of A. taxiformis and P. spiralis led to identification of sixteen compounds by GC-MS, as eicosapentaenoic and arachidonic acids, in addition to nucleosides uridine and thymidine, obtained from A. taxiformis, and uridine and inosine, obtained from P. spiralis. The crude extracts and fractions from the studied algae were evaluated against phytopathogenic fungus Cladosporium sphaerospermum, against acetylcholinesterase enzyme and against tumor cell lines of ovarian carcinoma (OVCAR-8), human colon adenocarcinoma (HCT-116) and human glioblastoma (SF-295). No significant antifungal or acetylcholinesterase activities were observed, whereas the hexane and butanol fractions from both algae showed moderate cytotoxicity against SF-295 cell line. As for the study on the microorganisms associated to algae, seven endophytic fungi strains were isolated from A. taxiformis and three strains from P. spiralis, which were cultivated in potato dextrose broth (PDB) prepared with either sea water or ultra pure water. After incubation, the ethyl acetate crude extracts were obtained and evaluated for their chemical and biological profiles, by HPLC, NMR and in vitro bioassays, respectively. After the preliminary prospection, Nemania bipapillata (AT-05), Sarocladium strictum (PS-01), Annulohypoxylon stygium (AT-03) and Hypoxylon sp. (AT-06) were selected for further investigation. The study of N. bipapillata, cultivated in sea water and PDB, led to isolation of diketopiperazine cyclo(Pro-Tyr), tyrosol and isocoumarins, (3R)-5-hydroxymethylmellein and (3R)-5-carboxymellein. Cultivation of this fungal strain in ultra pure water and PDB afforded two botryane-type norsesquiterpenes and three sesquiterpenes, unprecedent compounds in the literature and one known, 4β-acetoxy-9β,10β,15α-trihydroxyprobotrydial. Analysis of the crude extract from S. strictum, cultivated in ultra pure water and PDB, afforded a mixture of two diketopiperazines, in addition to isoflavone daidzein and six natural phthalates, including two novel ones which had been neither described in the literature nor synthesized. A. stygium and Hypoxylon sp. were cultivated in sea water and PDB, and A. stygium afforded pyrogallol, which was active against Escherichia coli and methicilin-resistant Staphylococcus aureus (MRSA), in addition to tyrosol and (˗)-(3R,4R)-3,4,5-trihydroxy-1-tetralone. Hypoxylon sp. afforded (3R)-scytalone, (3R,4R)-4-hydroxy-scytalone and daidzein. Such results highlight the importance of research on marine organisms and their associated microorganisms, and contribute to the knowledge of chemodiversity of marine organisms from the still chemically underexplored Brazilian coast.

A population of a critically endangered species Spiranthes spiralis was discovered in 1980 in the National Natural Monument Pastviště u Fínů near village Albrechtice, close to Sušice city. Since 1985 the number of flowering individuals in this population has been annually monitored. Since autumn 1998 all the specimen found there have been marked and biometrically measured. During these periods (12 or 26 years, respectively), large year-on-year fluctuations in the number of flowering plants and in the survival of the individual rosettes have been recorded. The main aim of my work was to assess the effect of weather conditions (temperature, precipitation, the number of days of snow) on the population dynamics and on the fitness of plants (leaf area, probability of flowering and probability of death). The year-round lower temperature and the wet end of autumn during the previous year (t-1) together with the wet spring of the following year (t) had a positive effect on the leaf area during the period of maximal rosette growth (end May in the year t). The probability of flowering was positively affected by the lower temperatures in May and June in the previous year (t-1) and in August just before flowering (year t). The probability of death (in the year t) was increased when the March precipitation (in t) and October temperatures (in t-1) were low. The average number of seeds in the capsule was 1528 ? 885 (s.d.). The number of flowers was positively correlated with the number of mature capsules. However, it did not affect the ratio of mature capsules. Capsules developed on average from 44% ? 24.6 % (s.d.) of the flowers. The average life time of individual plant cohorts was 4.7 years. The number of rosettes per each position was variable from 1 to 7 rosettes (73.2% positions had only 1 rosette). The annual life cycle of the underground organs is described at the end of the thesis.