Mechanisms of cell transformation induced by polyomavirus

Polyomavirus is a DNA tumor virus that induces a variety of tumors in mice. Its genome encodes three proteins, namely large T (LT), middle T (MT), and small T (ST) antigens, that have been implicated in cell transformation and tumorigenesis. LT is associated with cell immortalization, whereas MT plays an essential role in cell transformation by binding to and activating several cytoplasmic proteins that participate in growth factor-induced mitogenic signal transduction to the nucleus. The use of different MT mutants has led to the identification of MT-binding proteins as well as analysis of their importance during cell transformation. Studying the molecular mechanisms of cell transformation by MT has contributed to a better understanding of cell cycle regulation and growth control.

Oncogene-mediated downregulation of RECK, a novel transformation suppressor gene

The RECK gene was initially isolated as a transformation suppressor gene encoding a novel membrane-anchored glycoprotein and later found to suppress tumor invasion and metastasis by regulating matrix metalloproteinase-9. Its expression is ubiquitous in normal tissues, but undetectable in many tumor cell lines and in fibroblastic lines transformed by various oncogenes. The RECK gene promoter has been cloned and characterized. One of the elements responsible for the oncogene-mediated downregulation of mouse RECK gene is the Sp1 site, where the Sp1 and Sp3 factors bind. Sp1 transcription factor family is involved in the basal level of promoter activity of many genes, as well as in dynamic regulation of gene expression; in a majority of cases as a positive regulator, or, as exemplified by the oncogene-mediated suppression of RECK gene expression, as a negative transcription regulator. The molecular mechanisms of the downregulation of mouse RECK gene and other tumor suppressor genes are just beginning to be uncovered. Understanding the regulation of these genes may help to develop strategies to restore their expression in tumor cells and, hence, suppress the cells' malignant behavior.

Vahinkoeläinsodasta psykologiseen omistajuuteen. Petokonfliktien historiallinen tausta ja nykypäivän hallinta

Suurpetojen kannanhoitoon, ja etenkin suden kannanhoitoon liittyvä monitahoinen konfl ikti esiintyy jännitteinä paikallisyhteisöjen ja keskushallinnon, maaseudun ja kaupunkien sekä maallikoiden ja tutkijoiden välillä. Suurpetopolitiikan legitimiteettikriisi näkyy kansallisen kannanhoidon tavoitteiden ja toimenpiteiden kiistämisenä passiivisin ja aktiivisin toimin. Tällä ajankohtaisella ongelmalla on mittavat historialliset juuret. Luonnon ja ihmisen välinen suhde on ollut jatkuvaa tasapainottelua konfl iktien ja niiden hallinnan kanssa, ja suurpedot ovat väistämättä olleet konfl iktin keskiössä lajityypillisten piirteidensä vuoksi. Tämän tutkimuksen tavoitteena on osoittaa ympäristöhistoriallisen tutkimusotteen kautta suomalaisen vahinkoeläinhistorian keskeiset toimet ja toimijat, sekä ymmärtää vahinkoeläinten kannanhoidon tavoite- ja toimenpideasettelun vaikutukset eläinpopulaatioihin historiallisessa ja ekologisessa kontekstissa. Tutkimuksen toinen tavoite on tuottaa synteesi nykypäivän suurpetojen kannanhoidon tavoite- ja toimenpiteiden tarkoituksenmukaisuudesta ja vaikuttavuudesta historiallisessa kontekstissa ja esittää uudenlainen lähestymismalli sosiaalisesti kestävämmälle suurpetopolitiikalle. Vahinkoeläinhistoriaa käsitellään deduktiivisella ja rekonstruktiivisella tutkimusotteella käyttäen aineistona lakitekstejä, maksettuja tapporahoja, sanomalehtikirjoituksia, sidosryhmien kirjoituksia sekä eläintieteellisiä julkaisuja. Etenkin laeissa ja asetuksissa eri eläimistä asetetut tapporahat ja toisaalta saalistilastojen perusteella maksetut palkkiot on nostettu tässä tutkimuksessa merkittävään rooliin asenteiden tulkinnan välineenä. Tarkastelu ulotetaan nisäkkäiden lisäksi myös lintuihin, jotka ovat edellä mainitun aineiston valossa olleet merkittävä vainottu eläinryhmä. Nykypäivän petokonfl iktin tarkastelussa keskiöön nostetaan suurpetoasenteet, niiden muodostuminen ja vaikutus suurpetopolitiikan tavoitteiden ja toimenpiteiden kiistämisessä. Suurpetopolitiikan legitimiteettikriisiä tarkastellaan paikallisten uhmakkuutena hallintoa kohtaan ja tulkinta keinoista puuttua sosiopoliittiseen rikokseen rakennetaan tätä ajatusta vasten. Suurpetojen salakaatajat toimivat yhteisönsä puolesta ja saavat tukensa toimilleen yhteisöltään. Sosiopoliittinen rikos ei siten ole ainoastaan salakaatajien vaan sen sijaan yhteisön yhteinen. Salakaatajat ja paikallisyhteisö pyrkivät häivyttämään yhteiskunnassa viranomaisten ja sidosryhmien taholta toimintaan liittämää stigmaa ja siten oikeuttamaan tekonsa vallitsevissa olosuhteissa. Arvoristiriitoihin perustuvat konfl iktit ovat haasteellisia hallita ja lähtökohtana on oltava ymmärrys siitä, että etenkin suteen liittyvät jännitteet ja ristiriidat ihmisten välisissä suhteissa ovat väistämättömiä. Tunnistamalla historiallisen aineiston merkittävyys nykypäivän ongelmakeskeisen kannanhoidon ratkaisun tietopohjana on mahdollista rakentaa sosiaalisesti kestävämpää suurpetojen kannanhoitoa. Tässä väitöskirjatyössä painotetaan suurpetoihin liittyen ajatusta, jonka mukaan paikallisilta suurpetoalueilla eläviltä ihmisiltä tai sidosryhmien edustajilta ei edellytetä arvomaailman muuttumista, vaan hyväksytään heidän käsityksensä suurpetojen roolista vahingontekijöinä. Sen sijaan vahvistetaan suurpetojen välineellistä roolia paikallisyhteisöjen resurssina ja oleellisten sidosryhmien roolia yhteisön toimijoina psykologisen omistajuuden rakentamisen kautta. Suurpetojen kestävä kannanhoito vaatii siten riistahallinnon toimintakulttuurin muutosta ja uudenlaista suhdetta yhteiskunnan eri toimijoihin.

Transformation of carbon dioxide to diethyl carbonate over ceria and ceria-supported catalysts

Carbon dioxide is regarded, nowadays, as a primary anthropogenic greenhouse gas leading to global warming. Hence, chemical fixation of CO2 has attracted much attention as a possible way to manufacture useful chemicals. One of the most interesting approaches of CO2 transformations is the synthesis of organic carbonates. Since conventional production technologies of these compounds involve poisonous phosgene and carbon monoxide, there is a need to develop novel synthetic methods that would better match the principles of "Green Chemistry" towards protection of the environment and human health. Over the years, synthesis of dimethyl carbonate was under intensive investigation in the academia and industry. Therefore, this study was entirely directed towards equally important homologue of carbonic esters family namely diethyl carbonate (DEC). Novel synthesis method of DEC starting from ethanol and CO2 over heterogeneous catalysts based on ceria (CeO2) was studied in the batch reactor. However, the plausible drawback of the reaction is thermodynamic limitations. The calculated values revealed that the reaction is exothermic (ΔrHØ298K = ─ 16.6 J/ ) and does not occur spontaneously at rooms temperature (ΔrGØ 298K = 35.85 kJ/mol). Moreover, co-produced water easily shifts the reaction equilibrium towards reactants excluding achievement of high yields of the carbonate. Therefore, in-situ dehydration has been applied using butylene oxide as a chemical water trap. A 9-fold enhancement in the amount of DEC was observed upon introduction of butylene oxide to the reaction media in comparison to the synthetic method without any water removal. This result confirms that reaction equilibrium was shifted in favour of the desired product and thermodynamic boundaries of the reaction were suppressed by using butylene oxide as a water scavenger. In order to obtain insight into the reaction network, the kinetic experiments were performed over commercial cerium oxide. On the basis of the selectivity/conversion profile it could be concluded that the one-pot synthesis of diethyl carbonate from ethanol, CO2 and butylene oxide occurs via a consecutive route involving cyclic carbonate as an intermediate. Since commercial cerium oxide suffers from the deactivation problems already after first reaction cycle, in-house CeO2 was prepared applying room temperature precipitation technique. Variation of the synthesis parameters such as synthesis time, calcination temperature and pH of the reaction solution turned to have considerable influence on the physico-chemical and catalytic properties of CeO2. The increase of the synthesis time resulted in high specific surface area of cerium oxide and catalyst prepared within 50 h exhibited the highest amount of basic sites on its surface. Furthermore, synthesis under pH 11 yielded cerium oxide with the highest specific surface area, 139 m2/g, among all prepared catalysts. Moreover, CeO2─pH11 catalyst demonstrated the best catalytic activity and 2 mmol of DEC was produced at 180 oC and 9 MPa of the final reaction pressure. In addition, ceria-supported onto high specific surface area silicas MCM-41, SBA-15 and silica gel were synthesized and tested for the first time as catalysts in the synthesis of DEC. Deposition of cerium oxide on MCM-41 and SiO2 supports resulted in a substantial increase of the alkalinity of the carrier materials. Hexagonal SBA-15 modified with 20 wt % of ceria exhibited the second highest basicity in the series of supported catalysts. Evaluation of the catalytic activity of ceria-supported catalysts showed that reaction carried out over 20 wt % CeO2-SBA-15 generated the highest amount of DEC.

Long-term efficacy of a rural community-based integrated intervention for prevention and management of chronic obstructive pulmonary disease: a cluster randomized controlled trial in China's rural areas

This study aimed to assess the efficacy of a rural community-based integrated intervention for early prevention and management of chronic obstructive pulmonary disease (COPD) in China. This 18-year cluster-randomized controlled trial encompassing 15 villages included 1008 patients (454 men and 40 women in the intervention group [mean age, 54 ± 10 years]; 482 men and 32 women in the control group [mean age, 53 ± 10 years]) with confirmed COPD or at risk for COPD. Villages were randomly assigned to the intervention or the control group, and study participants residing within the villages received treatment accordingly. Intervention group patients took part in a program that included systematic health education, smoking cessation counseling, and education on management of COPD. Control group patients received usual care. The groups were compared after 18 years regarding the incidence of COPD, decline in lung function, and mortality of COPD. COPD incidence was lower in the intervention group than in the control group (10% vs 16%, <0.05). A decline in lung function was also significantly delayed in the intervention group compared to the control group of COPD and high-risk patients. The intervention group showed significant improvement in smoking cessation compared with the control group, and smokers in the intervention group had lower smoking indices than in the control group (350 vs 450, <0.05). The intervention group also had a significantly lower cumulative COPD-related death rate than the control group (37% vs 47%, <0.05). A rural community-based integrated intervention is effective in reducing the incidence of COPD among those at risk, delaying a decline in lung function in COPD patients and those at risk, and reducing mortality of COPD.

Identificação de antocianidinas em acerolas do Banco Ativo de Germoplasma da Universidade Federal Rural de Pernambuco

As antocianinas, pigmentos responsáveis pela cor vermelha da acerola madura, foram extraídas e purificadas de 12 genótipos cultivados no Banco Ativo de Germoplasma da Universidade Federal Rural de Pernambuco, com o objetivo de determinar a sua composição. As antocianinas e suas respectivas agliconas, obtidas pela hidrólise ácida, foram separadas por cromatografia líquida de alta eficiência (CLAE) usando uma coluna de fase reversa (C18). A identificação foi realizada pela ordem de eluição e pelos tempos de retenção dos padrões de referência e das antocianidinas obtidas por hidrólise ácida de uvas Isabel, Patrícia e Red Globe, ameixa, cebola roxa, morango e da casca de manga Tommy Atkins. Os cromatogramas obtidos demonstraram que o perfil antociânico dos genótipos de acerola é relativamente simples, apresentando de três a cinco picos comuns entre eles. Após hidrólise ácida foram obtidas somente duas agliconas identificadas como cianidina e pelargonidina. Comparando os cromatogramas das antocianinas e das antocianidinas e, avaliando os tempos de retenção, foi constatada a presença de antocianinas com diferentes graus de glicosilação e ausência de ácidos acilados em suas moléculas e que as agliconas identificadas, cianidina e pelargonidina, encontravam-se em diferentes proporções nos genótipos estudados.

Food access and consumption in a rural settlement in Castanhal, PA, Brazil

Abstract The study aimed to assess the food accessibility and consumption among families in the Cupiúba rural settlement, in the city of Castanhal, Pará, Brazil. It was found that the access to food is worrying and indicated that most families are in food insecurity conditions. Moreover, income and food safety level were associated. The consumption of the settler families comprises mainly high-energy, low-nutrient content foods, characterized by the low intake of fruits and vegetables and the introduction of processed foods with high energy density and sugar-added beverages, although the traditional dietary habits (rice and beans) are still present. This configures a diet at risk for important nutritional deficits, obesity, and many non-communicable chronic diseases.

Situando o desenvolvimento rural no Brasil: o contexto e as questões em debate

Addressing rural development discussions in Brazil: context and issues of debate. The work analyzes the main theoretical trends and subjects that integrate the recent Brazilian debate about rural development. We agued that the agenda of the rural development in Brazil, on which actively participate scholars, organizations and institutions, have been formulated by the State and the public politics implemented since the beginning of the 1990. Among the factors that had influenced the emergency of the debate about rural development is distinguished the increasing social and political legitimating of family farming and the agrarian reform, the reorientation of the state policies, the increasing sharply political and ideological quarrels with the agribusiness wing and the matters about sustainability. It is also argued that the analytical and interpretative references that have being used by the scholars are still diffuse and varied, but has been capable to influence the policy makers.

Premières conséquences de la guerre : transformation mentale des peuples... / Dr Gustave Le Bon

Collection : Bibliothèque de philosophie scientifique