Pregnancy rates and predictors in women with HIV/AIDS in Rio de Janeiro, Southeastern Brazil

OBJECTIVE: To assess incidence and predictors of first pregnancy among women with HIV/AIDS. METHODS: Prospective cohort study was conducted in Rio de Janeiro, southeastern Brazil, between 1996 and 2003. This study comprised 225 women with HIV/AIDS followed up until their first pregnancy or first censored event (hysterectomy, tubal ligation, menopause, 50 years of age, loss to follow-up, death or the end of December 2003). Pregnancy and abortion rates were estimated, and Cox proportional hazards models were used to identify baseline characteristics associated with pregnancy risk. RESULTS: The women were followed up for 565 person/years with a median follow-up of 3 years per women. The mean age was 32 years (SD: 7), and 54.7% were white. There were 60 pregnancies in 39 women, and 18 were terminated (induced abortions), accounting for a rate of 6.9% and 2.1% women/year, respectively. Repeated pregnancies occurred in 33.3% of the women (13/39). Higher pregnancy risk was seen among younger women (HR=3.42; 95%CI: 1.69;6.95) and those living with their partners (HR=1.89; 95%CI: 1.00;3.57). Lower pregnancy risk was associated with higher education level (HR=0.43; 95%CI: 0.19;0.99) and use of antiretroviral therapy (HR=061; 95%CI: 0.31;1.17). CONCLUSIONS: Lower pregnancy rates were found in our cohort than in the general population. Sociodemographic characteristics should be taken into consideration in the management of reproductive health in HIV-positive childbearing age women. Reproductive and family planning counseling must be incorporated into HIV/AIDS programs for women to help preventing HIV transmission to their partners and offspring.

Hospitalization rates for pneumococcal disease in Brazil, 2004 - 2006

OBJECTIVE: To estimate hospitalization rates for pneumococcal disease based on the Brazilian Hospital Information System (SIH). METHODS: Descriptive study based on the Hospital Information System of Brazilian National Health System data from January 2004 to December 2006: number of hospitalizations and deaths for pneumococcal meningitis, pneumococcal sepsis, pneumococcal pneumonia and Streptococcus pneumoniae as the cause of diseases reported in Brazil. Data from the 2003 Brazilian National Household Survey were used to estimate events in the private sector. Pneumococcal meningitis cases and deaths reported to the Notifiable Diseases Information System during the study period were also analyzed. RESULTS: Pneumococcal disease accounted for 34,217 hospitalizations in the Brazilian National Health System (0.1% of all hospitalizations in the public sector). Pneumococcal pneumonia accounted for 64.8% of these hospitalizations. The age distribution of the estimated hospitalization rates for pneumococcal disease showed a "U"-shape curve with the highest rates seen in children under one (110 to 136.9 per 100,000 children annually). The highest hospital case-fatality rates were seen among the elderly, and for sepsis and meningitis. CONCLUSIONS: PD is a major public health problem in Brazil. The analysis based on the SIH can provide an important input to pneumococcal disease surveillance and the impact assessment of immunization programs.

Overexpression of tumour-associated carbohydrate antigen sialyl-Tn in advanced bladder tumours

Little is known on the expression of the tumour-associated carbohydrate antigen sialyl-Tn (STn), in bladder cancer. We report here that 75% of the high-grade bladder tumours, presenting elevated proliferation rates and high risk of recurrence/progression expressed STn. However, it was mainly found in non-proliferative areas of the tumour, namely in cells invading the basal and muscle layers. STn was also found in tumour-adjacent mucosa, which suggests its dependence on a field effect of the tumour. Furthermore, it was not expressed by the normal urothelium, demonstrating the cancer-specific nature of this antigen. STn expression correlated with that of sialyltransferase ST6GalNAc.I, its major biosynthetic enzyme. The stable expression of ST6GalNAc.I in the bladder cancer cell line MCR induced STn expression and a concomitant increase of cell motility and invasive capability. Altogether, these results indicate for the first time a link between STn expression and malignancy in bladder cancer. Hence, therapies targeting STn may constitute new treatment approaches for these tumours.

Caracterização molecular da resistência a antimicrobianos em Escherichia coli produtoras de β-lactamases de espectro alargado isoladas em cães e estudo da partilha de clones bacterianos entre animais de companhia e coabitantes humanos

A pressão seletiva originada pelo uso excessivo de antimicrobianos na medicina humana e veterinária tem contribuído para a emergência de estirpes bacterianas multirresistentes, sendo os estudos mais escassos relativamente à sua presença nos animais de companhia. Porque os animais e os seus proprietários partilham o mesmo espaço habitacional, apresentando comportamentos de contacto próximo, existe uma hipótese elevada de transferência microbiana inter-espécie. Ante esta possibilidade é importante escrutinar o papel dos animais de companhia enquanto reservatórios de estirpes e de genes de resistência, bem como a sua envolvência na disseminação de estirpes bacterianas multirresistentes. Importa também, investigar o papel das superfícies e objetos domésticos partilhados por ambos, como potenciadores deste fenómeno. O objetivo deste trabalho foi, identificar o filogrupo e fazer a caracterização molecular dos genes que conferem resistência aos β-lactâmicos e às quinolonas, em quarenta isolados de Escherichia coli produtoras de β-lactamases de espectro alargado (ESBL), obtidas em zaragatoas fecais de cães consultados no Hospital Veterinário do ICBAS-UP. Complementarmente pretendeu-se inferir sobre a partilha de clones de Escherichia coli e Enterococcus spp. com elevadas resistências, em cinco agregados familiares (humanos e seus animais de companhia) assim como avaliar a potencial disseminação de estirpes multirresistentes no ambiente doméstico. Previamente foram recolhidas zaragatoas de fezes, pelo e mucosa oral dos animais e em alguns casos, dos seus proprietários, e ainda do ambiente doméstico. As zaragatoas foram processadas e as estirpes isoladas com base em meios seletivos. Foram realizados testes de suscetibilidade antimicrobiana de modo a estabelecer o fenótipo de resistência de cada isolado. O DNA foi extraído por varias metodologias e técnicas de PCR foram utilizadas para caracterização de filogrupos (Escherichia coli) e identificação da espécie (Enterococcus spp.). A avaliação da proximidade filogenética entre isolados foi efetuada por ERIC PCR e PFGE. No conjunto de quarenta isolados produtores de ESBL e/ou resistentes a quinolonas verificou-se que 47,5% pertenciam ao filogrupo A, havendo uma menor prevalência do filogrupo D (25,0%), B1 (17,5%), e B2 (10,0%).A frequência de resistência nestes isolados é factualmente elevada, sendo reveladora de uma elevada pressão seletiva. Com exceção de dois isolados, os fenótipos foram justificados pela presença de β-lactamases. A frequência da presença de genes foi: 47% blaTEM, 34% blaSHV, 24% blaOXA , 18% blaCTX-M-15, 8% blaCTX-M-2, 3% blaCTX-M-9. Nos isolados resistentes às quinolonas verificou-se maioritariamente a presença de mutações nos genes cromossomais gyrA e parC, e em alguns casos a presença de um determinante de resistência mediado por plasmídeo – qnrS. Nos cinco “agregados familiares” (humanos e animais) estudados foi observada uma partilha frequente de clones de E. coli e Enterococcus faecalis com múltiplas resistências, isolados em fezes e mucosa oral de cães e gatos e fezes e mãos dos respetivos proprietários, evidenciando-se assim uma possível transferência direta entre coabitantes (agregados A, C, D, E). Ficou também comprovado com percentagens de similaridade genotípica superiores a 94% que essa disseminação também ocorre para o ambiente doméstico, envolvendo objetos dos animais e de uso comum (agregados A, E). Os resultados obtidos reforçam a necessidade de um uso prudente dos antimicrobianos, pois elevados padrões de resistências terão um impacto não só na qualidade de vida dos animais mas também na saúde humana. Adicionalmente importa sensibilizar os proprietários para a necessidade de uma maior vigilância relativamente às formas de interação com os animais, bem como para a adoção de medidas higiénicas cautelares após essa mesma interação.

Ligand-Induced structural changes in TEM‑1 probed by molecular dynamics and relative binding free energy calculations

The TEM family of enzymes has had a crucial impact on the pharmaceutical industry due to their important role in antibiotic resistance. Even with the latest technologies in structural biology and genomics, no 3D structure of a TEM- 1/antibiotic complex is known previous to acylation. Therefore, the comprehension of their capability in acylate antibiotics is based on the protein macromolecular structure uncomplexed. In this work, molecular docking, molecular dynamic simulations, and relative free energy calculations were applied in order to get a comprehensive and thorough analysis of TEM-1/ampicillin and TEM-1/amoxicillin complexes. We described the complexes and analyzed the effect of ligand binding on the overall structure. We clearly demonstrate that the key residues involved in the stability of the ligand (hot-spots) vary with the nature of the ligand. Structural effects such as (i) the distances between interfacial residues (Ser70−Oγ and Lys73−Nζ, Lys73−Nζ and Ser130−Oγ, and Ser70−Oγ−Ser130−Oγ), (ii) side chain rotamer variation (Tyr105 and Glu240), and (iii) the presence of conserved waters can be also influenced by ligand binding. This study supports the hypothesis that TEM-1 suffers structural modifications upon ligand binding.

A survey in Portuguese X-ray fluoroscopy equipment: dose rates and image quality

X-ray fluoroscopy is essential in both diagnosis and medical intervention, although it may contribute to significant radiation doses to patients that have to be optimised and justified. Therefore, it is crucial to the patient to be exposed to the lowest achievable dose without compromising the image quality. The purpose of this study was to perform an analysis of the quality control measurements, particularly dose rates, contrast and spatial resolution of Portuguese fluoroscopy equipment and also to provide a contribution to the establishment of reference levels for the equipment performance parameters. Measurements carried out between 2007 and 2013 on 143 fluoroscopy equipment distributed by 34 nationwide health units were analysed. The measurements suggest that image quality and dose rates of Portuguese equipment are congruent with other studies, and in general, they are as per the Portuguese law. However, there is still a possibility of improvements intending optimisation at a national level.

Transport mechanism in ionic liquid membranes and the study of thiomersal biodegradation

The initial goal of this work was the development of a supported liquid membrane (SLM) bioreactor for the remediation of vaccine production effluents contaminated with a highly toxic organomercurial – thiomersal. Therefore, two main aspects were focused on: 1) the development of a stable supported liquid membrane – using room temperature ionic liquids (RTILs) – for the selective transport of thiomersal from the wastewater to a biological compartment, 2) study of the biodegradation kinetics of thiomersal to metallic mercury by a Pseudomonas putida strain. The first part of the work focused on the evaluation of the physicochemical properties of ionic liquids and on the SLMs’ operational stability. The results obtained showed that, although it is possible to obtain a SLM with a high stability, water possesses nonnegligible solubility in the RTILs studied. The formation of water clusters inside the hydrophobic ionic liquid was identified and found to regulate the transport of water and small ions. In practical terms, this meant that, although it was possible to transport thiomersal from the vaccine effluent to the biological compartment, complete isolation of the microbial culture could not be guaranteed and the membrane might ultimately be permeable to other species present in the aqueous vaccine wastewater. It was therefore decided not to operate the initially targeted integrated system but, instead, the biological system by itself. Additionally, attention was given to the development of a thorough understanding of the transport mechanisms involved in the solubilisation and transport of water through supported liquid membranes with RTILs as well as to the evaluation of the effect of water uptake by the SLM in the transport mechanisms of water-soluble solutes and its effect on SLM performance. The results obtained highlighted the determinant role played by water – solubilised inside the ionic liquids – on the transport mechanism. It became clear that the transport mechanism of water and water-soluble solutes through SLMs with [CnMIM][PF6] RTILs was regulated by the dynamics of water clusters inside the RTIL, rather than by molecular diffusion through the bulk of the ionic liquid. Although the stability tests vi performed showed that there were no significant losses of organic phase from the membrane pores, the formation of water clusters inside the ionic liquid, which constitute new, non-selective environments for solute transport, leads to a clear deterioration of SLM performance and selectivity. Nevertheless, electrical impedance spectroscopy characterisation of the SLMs showed that the formation of water clusters did not seem to have a detrimental effect on the SLMs’ electrical characteristics and highlighted the potential of using this type of membranes in electrochemical applications with low resistance requirements. The second part of the work studied the kinetics of thiomersal degradation by a pure culture of P. putida spi3 strain, in batch culture and using a synthe tic wastewater. A continuous ly stirred tank reactor fed with the synthetic wastewater was also operated and the bioreactor’s performance and robustness, when exposed to thiomersal shock loads, were evaluated. Finally, a bioreactor for the biological treatment of a real va ccine production effluent was set up and operated at different dilution rates. Thus it was possible to treat a real thiomersal-contaminated effluent, lowering the outlet mercury concentration to values below the European limit for mercury effluent discharges.

Molecular mobility of n-ethylene glycol dimethacrylate glass formers upon free radical polymerization

Quando um líquido evita a cristalização durante o arrefecimento, diz-se que entra no estado sobrearrefecido. Se a temperatura continuar a diminuir, o consequente aumento da viscosidade reflecte-se na mobilidade molecular de tal maneira que os tempos característicos se tornam da mesma ordem de grandeza que os tempos acessíveis experimentalmente. Se o arrefecimento continuar, o líquido altamente viscoso acaba por vitrificar, i.e. entra no estado vítreo onde apenas os movimentos locais são permitidos. Os monómeros da família n -etileno glicol dimetacrilato ( n -EGDMA, para n = 1 até 4, que constituem o objecto deste estudo, facilmente evitam a cristalização, sendo pois bons candidatos para estudar a mobilidade molecular nos estados sobrearrefecido e vítreo. A Espectroscopia de Relaxação Dieléctrica (DRS) foi a técnica escolhida para obter informação detalhada sobre a sua dinâmica molecular (Capítulos 1 e 2). A primeira parte deste trabalho consistiu na caracterização dieléctrica dos processos de relaxação existentes acima e abaixo da temperatura de transição vítrea (g T ), a qual aumenta com o aumento do peso molecular (w M ), sendo este resultado confirmado por Calorimetria Diferencial de Varrimento (DSC). No que respeita ao processo cooperativo a , associado à transição vítrea, e ao processo secundário b, observa-se uma dependência com w M , enquanto que o outro processo secundário, g , aparenta ser independente deste factor (Capítulo 3). Nos capítulos seguintes, foram levadas a cabo diferentes estratégias com o objectivo de clarificar os mecanismos que estão na origem destas duas relaxações secundárias (b e g ), assim como conhecer a sua respectiva relação com a relaxação principal (a ). Do estudo, em tempo real, da polimerização isotérmica via radicais livres do TrEGDMA por Calorimetria de Varrimento Diferencial com Modulação de Temperatura (TMDSC), levado a cabo a temperaturas abaixo da g T do polímero final, concluem-se entre outros, dois importantes aspectos: i) que a vitrificação do polímero em formação conduz a graus de conversão relativamente baixos, e ii) que o monómero que está por reagir é expulso da rede polimérica que se forma, dando lugar a uma clara separação de fases (Capítulo 4). Com base nesta informação, o passo seguinte foi estudar separadamente a polimerização isotérmica do di-, tri- e tetra-EGDMA, dando especial atenção às alterações de mobilidade do monómero ainda por reagir. Com as restrições impostas pela formação de ligações químicas, as relaxações a e b detectadas no monómero tendem a desaparecer no novo polímero formado, enquanto que a relaxação g se mantém quase inalterada. Os diferentes comportamentos que aparecem durante a polimerização permitiram a atribuição da origem molecular dos processos secundários: o processo g foi associado ao movimento twisting das unidades etileno glicol, enquanto que a rotação dos grupos carboxilo foi relacionada com a relaxação b (Capítulo 5). No que respeita ao próprio polímero, um processo de relaxação adicional foi detectado, pol b , no poly-DEGDMA, poly-TrEGDMA e poly-TeEGDMA, com características similares ao encontrado nos poli(metacrilato de n -alquilo). Este processo foi confirmado e bem caracterizado aquando do estudo da copolimerização do TrEGDMA com acrilato de metilo (MA) para diferentes composições (Capítulo 6). Para finalizar, o EGDMA, o elemento mais pequeno da família de monómeros estudada, além de vitrificar apresenta uma marcada tendência para cristalizar quer a partir do estado líquido ou do estado vítreo. Durante a cristalização, a formação de uma fase rígida afecta principalmente o processo a , cuja intensidade diminui sem no entanto se observarem modificações significativas na dependência do tempo de relaxação característico com a temperatura. Por outro lado, o processo secundário b torna-se melhor definido e mais estreito, o que pode ser interpretado em termos de uma maior homogeneidade dos micro-ambientes associados aos movimentos locais(Capítulo 7).

Spatial study of homicide rates in the state of Bahia, Brazil, 1996-2010

OBJECTIVE To analyze the spatial distribution of homicide mortality in the state of Bahia, Northeastern Brazil. METHODS Ecological study of the 15 to 39-year old male population in the state of Bahia in the period 1996-2010. Data from the Mortality Information System, relating to homicide (X85-Y09) and population estimates from the Brazilian Institute of Geography and Statistics were used. The existence of spatial correlation, the presence of clusters and critical areas of the event studied were analyzed using Moran’s I Global and Local indices. RESULTS A non-random spatial pattern was observed in the distribution of rates, as was the presence of three clusters, the first in the north health district, the second in the eastern region, and the third cluster included townships in the south and the far south of Bahia. CONCLUSIONS The homicide mortality in the three different critical areas requires further studies that consider the socioeconomic, cultural and environmental characteristics in order to guide specific preventive and interventionist practices.

Molecular diversity of bla genes in Klebsiella pneumoniae and Escherichia coli isolates

Dissertation presented to obtain a Ph.D. degree in Biology, speciality Microbiology, by Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Molecular mobility, composition and structure analysis in glycerol plasticised chitosan films

This study was developed with the purpose to investigate the effect of polysaccharide/plasticiser concentration on the microstructure and molecular dynamics of polymeric film systems, using transmission electron microscope imaging (TEM) and nuclear magnetic resonance (NMR) techniques. Experiments were carried out in chitosan/glycerol films prepared with solutions of different composition. The films obtained after drying and equilibration were characterised in terms of composition, thickness and water activity. Results show that glycerol quantities used in film forming solutions were responsible for films composition; while polymer/total plasticiser ratio in the solution determined the thickness (and thus structure) of the films. These results were confirmed by TEM. NMR allowed understanding the films molecular rearrangement. Two different behaviours for the two components analysed, water and glycerol were observed: the first is predominantly moving free in the matrix, while glycerol is mainly bounded to the chitosan chain. (C) 2013 Elsevier Ltd. All rights reserved.

Diagnóstico molecular da tuberculose bovina

Dissertação apresentada para a obtenção do Grau de Mestre em Genética Molecular e Biomedicina, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Electrorheology study of a series of LC cyanobiphenyls: Experimental and theoretical treatment

In this work we study the electro-rheological behaviour of a series of four liquid crystal (LC) cyanobiphenyls with a number of carbon atoms in the alkyl group, ranging from five to eight (5CB–8CB). We present the flow curves for different temperatures and under the influence of an external electric field, ranging from 0 to 3 kV/mm, and the viscosity as a function of the temperature, for the same values of electric field, obtained for different shear rates. Theoretical interpretation of the observed behaviours is proposed in the framework of the continuum theory of Leslie–Ericksen for low molecular weight nematic LCs. In our analysis, the director alignment angle is only a function of the ratio between the shear rate and the square of the electric field – boundary conditions are neglected. By fitting the theoretical model to the experimental data, we are able to determine some viscosity coefficients and the dielectric anisotropy as a function of temperature. To interpret the behaviour of the flow curves near the nematic–isotropic transitions, we apply the continuum theory of Olmsted–Goldbart, which extends the theory of Leslie–Ericksen to the case where the degree of alignment of the LC molecules can also vary.

Fracionamento do veneno Crotalus durissus terrificus por cromatografia de exclusão molecular

Através da técnica de cromatografia de exclusão molecular utilizando Sephadex G-75 foram estudadas as diferentes frações do veneno de Crotalus durissus terrificus, uma das serpentes peçonhentas mais comuns no Brasil. Foram obtidos 4 picos (correspondentes às frações 32, 60, 86 e 103) com peso molecular variando de 4.000 a 150.000. As frações de todo o diagrama de gel filtração foram triadas através de reação de imunoeletroforese a fim de se verificar suas cargas e velocidade de migração. As linhas de precipitação encontradas foram comparadas às 11 linhas apresentadas pela reação de imunoeletroforese do veneno total contra o soro anti-crotálico. Constatou-se que as frações de um mesmo pico apresentavam características próprias com exceção da fração 54 (subida do pico II) que mostrou diferenças significativas em relação à fração 60. Após a triagem foram escolhidas as frações de cada pico onde as linhas de precipitação foram mais nítidas e intensas, para estudo de identidade através da reação de difusão radial dupla e letalidade comparada a concentração de 0,0625 mg/ml do veneno total que corresponde a DL50 em camundongo pelo método de SPEARM & KÄRBER. As frações 32, 86 e 103 correspondentes respectivamente aos picos I, III e IV apresentaram letalidade nula ou negligenciada e a fração II foi a mais tóxica.

Influence of constraining and confinement in the molecular mobility of low molecular weight materials

Dissertation presented to obtain a Ph.D. Degree in Chemical Physics