A tripanossomose africana, ou doença do sono, como é popularmente conhecida, atingiu 25 mil pessoas só em 1995. Estima-se que a doença seja responsável pela morte de 10.000 pessoas a cada ano, segundo os dados da Organização Mundial da Saúde. Sua distribuição é exclusivamente africana, devido ao fato de sua transmissão depender da Tsé-Tsé, mosca do gênero Glossina que encontra lá condições favoráveis para sua proliferação. Atualmente os medicamentos existentes não são eficientes e devem ser ministrados em doses altas, provocando graves efeitos colaterais. O parasita Tripanosoma brucei, na forma encontrada no sangue dos mamíferos (tripomastigota), é o responsável pela doença e, assim como toda a família Trypanosomatidea, é altamente dependente de glicose. Esses parasitas consomem a quantidade de glicose equivalente à sua massa em aproximadamente sete horas. A via glicolítica torna-se, portanto, chave para o desenvolvimento de inibidores que possam ser utilizados no combate a estes parasitas. Nesse sentido, temos realizado estudos com a enzima glicose-6-fosfato isomerase (glucose-6-fosfato isomerase; Phosphoglucose Isomerase PGI; EC 5.3.1.9), responsável pela isomerização reversível da D-glicose-6-fosfato e D-frutose-6-fosfato e participa na glicólise como a segunda enzima da via. Os trabalhos realizados até aqui culminaram na sua expressão em forma recombinante, purificação através de coluna de afinidade, e caracterizações enzimáticas. Sua atividade específica foi determinada através de métodos já estabelecidos encontrados na literatura. O IC50 da enzima frente a quatro inibidores da reação foi determinado. O trabalho finaliza com a construção de um modelo estrutural da enzima determinado através de métodos de modelagem molecular por homologia. / The African trypanosomiasis, or sleeping sickness as is popularly known, affected 25 thousand people only in 1995. It is estimated that the disease is responsible for 10 thousand deaths per year, according to data provided from the World Health Organization (WHO). The distribution of the disease is exclusively African due to the transmission being dependent on the tsé-tsé vector. A fly, belonging to the Glossinia genus, finds in the African continent favorable conditions for its proliferation. Presently the existing drugs are not efficient and have to be applied in high dosage, resulting in severe side effects. The bloodstream form (tripomastigote) of the parasite Trypanosoma brucei is responsible for the disease and such as the whole Trypanosomatidae family is dependent on glucose. Those parasites consume a quantity of glucose equivalent to its mass in approximately seven hours. This characteristic results in the glycolitic pathway been a key target for drug development against those parasites. In this direction we are developing research with the enzyme glucose-6-phosphate isomerase (Phosphoglucose lsomerase PGI; EC 5.3.1.9) responsible for the reversible isomnerisation of D-glucose6-phosphate and D-fuctcose-6-phosphate. PGI participates as the second enzyme in the glycolytic pathway. The work developed so far resulted in the expression of the recombinant form of the parasite PGI, its affinity purification and enzimatic characterization. The specific activity was determined with established methods. The IC50 of four inhibitors was determined and a structural model of T brucei PGI was built by molecular modeling techniques.

A tripanossomose africana, ou doença do sono, como é popularmente conhecida, atingiu 25 mil pessoas só em 1995. Estima-se que a doença seja responsável pela morte de 10.000 pessoas a cada ano, segundo os dados da Organização Mundial da Saúde. Sua distribuição é exclusivamente africana, devido ao fato de sua transmissão depender da Tsé-Tsé, mosca do gênero Glossina que encontra lá condições favoráveis para sua proliferação. Atualmente os medicamentos existentes não são eficientes e devem ser ministrados em doses altas, provocando graves efeitos colaterais. O parasita Tripanosoma brucei, na forma encontrada no sangue dos mamíferos (tripomastigota), é o responsável pela doença e, assim como toda a família Trypanosomatidea, é altamente dependente de glicose. Esses parasitas consomem a quantidade de glicose equivalente à sua massa em aproximadamente sete horas. A via glicolítica torna-se, portanto, chave para o desenvolvimento de inibidores que possam ser utilizados no combate a estes parasitas. Nesse sentido, temos realizado estudos com a enzima glicose-6-fosfato isomerase (glucose-6-fosfato isomerase; Phosphoglucose Isomerase PGI; EC 5.3.1.9), responsável pela isomerização reversível da D-glicose-6-fosfato e D-frutose-6-fosfato e participa na glicólise como a segunda enzima da via. Os trabalhos realizados até aqui culminaram na sua expressão em forma recombinante, purificação através de coluna de afinidade, e caracterizações enzimáticas. Sua atividade específica foi determinada através de métodos já estabelecidos encontrados na literatura. O IC50 da enzima frente a quatro inibidores da reação foi determinado. O trabalho finaliza com a construção de um modelo estrutural da enzima determinado através de métodos de modelagem molecular por homologia. / The African trypanosomiasis, or sleeping sickness as is popularly known, affected 25 thousand people only in 1995. It is estimated that the disease is responsible for 10 thousand deaths per year, according to data provided from the World Health Organization (WHO). The distribution of the disease is exclusively African due to the transmission being dependent on the tsé-tsé vector. A fly, belonging to the Glossinia genus, finds in the African continent favorable conditions for its proliferation. Presently the existing drugs are not efficient and have to be applied in high dosage, resulting in severe side effects. The bloodstream form (tripomastigote) of the parasite Trypanosoma brucei is responsible for the disease and such as the whole Trypanosomatidae family is dependent on glucose. Those parasites consume a quantity of glucose equivalent to its mass in approximately seven hours. This characteristic results in the glycolitic pathway been a key target for drug development against those parasites. In this direction we are developing research with the enzyme glucose-6-phosphate isomerase (Phosphoglucose lsomerase PGI; EC 5.3.1.9) responsible for the reversible isomnerisation of D-glucose6-phosphate and D-fuctcose-6-phosphate. PGI participates as the second enzyme in the glycolytic pathway. The work developed so far resulted in the expression of the recombinant form of the parasite PGI, its affinity purification and enzimatic characterization. The specific activity was determined with established methods. The IC50 of four inhibitors was determined and a structural model of T brucei PGI was built by molecular modeling techniques.

Information gathered socially online is a key feature of the growth and development of modern society. Presently the Internet is a platform for the distribution of data. Millions of people use Online Social Networks daily as a tool to get updated with social, political, educational or other occurrences. In many cases information derived from an Online Social Network is acted upon and often shared with other networks, without further assessments or judgments. Many people do not check to see if the information shared is credible. A user may trust the information generated by a close friend without questioning its credibility, in contrast to a message generated by an unknown user. This work considers the concept of credibility in the wider sense, by proposing whether a user can trust the service provider or even the information itself. Two key components of credibility have been explored; trustworthiness and expertise. Credibility has been researched in the past using Twitter as a validation tool. The research was focused on automatic methods of assessing the credibility of sets of tweets using analysis of microblog postings related to trending topics to determine the credibility of tweets. This research develops a framework that can assist the assessment of the credibility of messages in Online Social Networks. Four types of credibility are explored (experienced, surface, reputed and presumed credibility) resulting in a credibility hierarchy. To determine the credibility of messages generated and distributed in Online Social Networks, a virtual network is created, which attributes nodes with individual views to generate messages in the network at random, recording data from a network and analysing the data based on the behaviour exhibited by agents (an agent-based modelling approach). The factors considered for the experiment design included; peer-to-peer networking, collaboration, opinion formation and network rewiring. The behaviour of agents, frequency in which messages are shared and used, the pathway of the messages and how this affects credibility of messages is also considered. A framework is designed and the resulting data are tested using the design. The resulting data generated validated the framework in part, supporting an approach whereby the concept of tagging the message status assists the understanding and application of the credibility hierarchy. Validation was carried out with Twitter data acquired through twitter’s Application Programming Interface (API). There were similarities in the generation and frequency of the message distributions in the network; these findings were also recorded and analysed using the framework proposed. Some limitations were encountered while acquiring data from Twitter, however, there was sufficient evidence of correlation between the simulated and real social network datasets to indicate the validity of the framework.