Base molecular da hemocromatose hereditária não-clássica em Portugal

A Hemocromatose Hereditária (HH) é uma doença autossómica recessiva caracterizada pela absorção excessiva de ferro a nível intestinal e sua acumulação em órgãos vitais, podendo originar cardiomiopatia, cirrose e carcinoma hepatocelular. O correspondente diagnóstico molecular é obtido pela associação com genótipos específicos no gene HFE (homozigotia para p.Cys282Tyr ou heterozigotia composta p.Cys282Tyr/p.His63Asp). Contudo, nos países do sul da Europa, cerca de um terço dos doentes com diagnóstico clínico de HH não apresenta os referidos genótipos. Para identificar a base molecular da HH não-clássica em Portugal usaram-se metodologias de pesquisa geral de variantes genéticas (SSCP e dHPLC), Next-Generation Sequencing (NGS) e sequenciação de Sanger, cobrindo seis genes relacionados com o metabolismo do ferro em 303 doentes. Identificaram-se 69 variantes diferentes e de vários tipos, por ex. missense, nonsense, de splicing, que perturbam a transcrição do gene ou a regulação da tradução do mRNA. Seguidamente, realizaram-se estudos in silico e in vitro para esclarecer o significado etiológico de algumas das novas variantes. Concluiu-se que a base molecular desta patologia é bastante heterogénea e que a NGS é uma ferramenta adequada para efetuar a análise simultânea dos vários genes num grande número de amostras. Contudo, o estabelecimento da relevância clínica de algumas variantes requer a realização de estudos funcionais.

Genotoxicity biomarkers: application in histopathology laboratories

Most cancers results from man-made and natural environmental exposures (such as tobacco smoke; chemical pollutants in air, water, food, drugs; radon; and infectious agents) acting in concert with both genetic and acquired characteristics. It has been estimated that without these environmental factors, cancer incidence would be dramatically reduced, by as much as 80%-90%. The modulation of environmental factors by host susceptibility was rarely evaluated. However, within the past few years, the interaction between environmental factors and host susceptibility factors has become a very active area of research. Molecular biology as a tool for use in epidemiological studies has significant potential in strengthening the identification of cancers associated with environmental exposures related to lifestyle, occupation, or ambient pollution. In molecular epidemiology, laboratory methods are employed to document the molecular basis and preclinical effects of environmental carcinogenesis. Molecular epidemiology has become a major field of research and considerable progress has been made in validation and application of biomarkers and its greatest contribution has been the insights provided into interindividual variation in human cancer risk and the complex interactions between environmental factors and host susceptibility factors, both inherited and acquired, in the multistage process of carcinogenesis.

Cancer incidence in eighteen cities of the State of São Paulo, Brazil

OBJECTIVE: As in Brazil cancer registries are mostly based on large cities, there are no estimates per state or per region and information on the disease incidence in the vast in-land areas is very scarce. An incidence survey was conducted in 18 major cities of the state of São Paulo, excluding the capital, aiming to collect information about cancer incidence in the state of São Paulo. METHODS: Of the 18 cities in state of São Paulo included in the survey, all had available resources for cancer management. Data from the year of 1991 were collected by the personnel of the Instituto Brasileiro de Geografia e Estatística (Brazilian Institute of Statistics), who were especially trained by the study coordinators at the Fundação Oncocentro de São Paulo (Cancer Center of São Paulo). The collected data were processed and analyzed at the Oncocentro. Data collection, processing, and analyses were performed according to the recommendations of the International Agency for Research on Cancer. RESULTS: Although some discrepancies were observed in cancer incidence rates between the cities, results obtained for all 18 cities combined were remarkably close to those recently found for the city of São Paulo in the year 1993. One remarkable finding was the relatively high cancer incidence rates in both sexes in the city of Santos. CONCLUSIONS: The very similar all-sites cancer incidence rates found in the year 1991, when compared to those for the city of São Paulo in the year 1993, are suggestive that all regions have common cancer-related factors. Nevertheless, other explanations, such as the inclusion in the study of prevalent cases, as well as of non-residents, may have occurred in both studies, biasing the results. There is a need of further studies to confirm the high cancer incidence in Santos.

Exposure to dust in poultry: the importance of task differences for detailed exposure assessment

Dust is a complex mixture of particles of organic and inorganic origin and different gases absorbed in aerosol droplets. In a poultry unit include dried faecal matter and urine, skin flakes, ammonia, carbon dioxide, pollens, feed and litter particles, feathers, grain mites, fungi spores, bacteria, viruses and their constituents. Dust particles vary in size and differentiation between particle size fractions is important in health studies in order to quantify penetration within the respiratory system. A descriptive study was developed in order to assess exposure to particles in a poultry unit during different operations, namely routine examination and floor turn over. Direct-reading equipment was used (Lighthouse, model 3016 IAQ). Particle measurement was performed in 5 different sizes (PM0.5; PM1.0; PM2.5; PM5.0; PM10). The chemical composition of poultry litter was also determined by neutron activation analysis. Normally, the litter of poultry pavilions is turned over weekly and it was during this operation that the higher exposure of particles was observed. In all the tasks considered PM5.0 and PM10.0 were the sizes with higher concentrations values. PM10 is what turns out to have higher values and PM0.5 the lowest values. The chemical element with the highest concentration was Mg (5.7E6 mg.kg-1), followed by K (1.5E4 mg.kg-1), Ca (4.8E3 mg.kg-1), Na (1.7E3 mg.kg-1), Fe (2.1E2 mg.kg-1) and Zn (4.2E1 mg.kg-1). This high presence of particles in the respirable range (<5–7μm) means that poultry dust particles can penetrate into the gas exchange region of the lung. Larger particles (PM10) present a range of concentrations from 5.3E5 and 3.0E6 mg/m3.

A comparison of two attenuation correction methods in 111In-Pentetriotide abdominal SPECT

Tomographic image can be degraded, partially by patient based attenuation. The aim of this paper is to quantitatively verify the effects of attenuation correction methods Chang and CT in 111In studies through the analysis of profiles from abdominal SPECT, correspondent to a uniform radionuclide uptake organ, the left kidney.

Modern cancer epidemiological research: genetic polymorphisms and environment

Individual cancer susceptibility seems to be related to factors such as changes in oncogenes and tumor suppressor genes expression, and differences in the action of metabolic enzymes and DNA repair regulated by specific genes. Epidemiological studies on genetic polymorphisms of human xenobiotics metabolizing enzymes and cancer have revealed low relative risks. Research considering genetic polymorphisms prevalence jointly with environmental exposures could be relevant for a better understanding of cancer etiology and the mechanisms of carcinogenesis and also for new insights on cancer prognosis. This study reviews the approaches of molecular epidemiology in cancer research, stressing case-control and cohort designs involving genetic polymorphisms, and factors that could introduce bias and confounding in these studies. Similarly to classical epidemiological research, genetic polymorphisms requires considering aspects of precision and accuracy in the study design.

Role on serine protease inhibitors in the pathogenisis of Steinernema carpocapsae

Tese de Doutoramento, Biologia (Biologia Celular e Molecular), 18 de Novembro de 2013, Universidade dos Açores.

Diversity of the Laurencia complex (Ceramiales, Rhodophyta) in Lusitanian Macronesia

10th International Phycological Congress, Orlando, Florida, USA, 4-10 de agosto 2013.

Determinants of salivary cotinine level: a population-based study in Brazil

OBJECTIVE: A cross-sectional population-based study was conducted to assess, in active smokers, the relationship of number of cigarettes smoked and other characteristics to salivary cotinine concentrations. METHODS: A random sample of active smokers aged 15 years or older was selected using a stepwise cluster sample strategy, in the year 2000 in Rio de Janeiro, Brazil. The study included 401 subjects. Salivary cotinine concentration was determined using gas chromatography with nitrogen-phosphorus detection. A standard questionnaire was used to collect demographic and smoking behavioral data. The relation between the number of cigarettes smoked in the last 24h and cotinine level was examined by means of a nonparametric fitting technique of robust locally weighted regression. RESULTS: Significantly (p<0.05) higher adjusted mean cotinine levels were found in subjects smoking their first cigarette within five minutes after waking up, and in those smoking 1-20 cigarettes in the last 24h who reported inhaling more than ½ the time. In those smoking 1-20 cigarettes, the slope was significantly higher for those subjects waiting for more than five minutes before smoking their first cigarette after waking up, and those smoking "light" cigarettes when compared with their counterparts. These heterogeneities became negligible and non-significant when subjects with cotinine >40 ng/mL per cigarette were excluded. CONCLUSIONS: There was found a positive association between self-reporting smoking five minutes after waking up, and inhaling more than ½ the time are consistent and higher cotinine levels. These can be markers of dependence and higher nicotine intake. Salivary cotinine proved to be a useful biomarker of recent smoking and can be used in epidemiological studies and smoking cessation programs.

Evaluation of 99mTc-Sestamibi as a potential tool to investigate PgP activity in inflammation

Introduction: In the XXI Century ’s Society the scientific investigation process has been growing steadily , and the field of the pharmaceutical research is one of the most enthusiastic and relevant . Here, it is very important to correlate observed functional alterations with possibly modified drug bio distribution patterns . Cancer, inflammation and inf ection are processes that induce many molecular intermediates like cytokines, chemokines and other chemical complexes that can alter the pharmacokinetics of many drugs. One cause of such changes is thought to be the modulator action of these complexes in t he P - Glyco p rotein activity, because they can act like inducers/inhibitors of MDR - 1 expression. This protein results from the expression of MDR - 1 gene, and acts as an ATP energy - dependent efflux pump, with their substrates including many drugs , like antiretrovirals, anticancers, anti - infectives, immunosuppressants, steroids or opioids . Objectives: Because of the lack of methods to provide helpful information in the investigation of in vivo molecular changes in Pgp activity during infection/infl ammation processes, and its value in the explanation of the altered drug pharmacokinetic, this paper want to evaluate the potential utility of 99m Tc - Sestamibi scintigraphy during this kind of health sciences investigation. Although the a im is indeed to create a technique to the in vivo study of Pgp activity, this preliminary Project only reaches the in vitro study phase, assumed as the first step in a n evaluation period for a new tool development. Materials and Methods: For that reason , we are performing in vitro studies of influx and efflux of 99m Tc - Sestamibi ( that is a substrate of Pgp) in hepatocytes cell line (HepG2). We are interested in clarify the cellular behavior of this radiopharmaceutical in Lipopolysaccharide(LPS) stimulated cells ( well known in vitro model of inflammation) to possibly approve this methodology. To validate the results, the Pgp expression will be finally evaluated using Western Blot technique. Results: Up to this moment , we still don’t have the final results, but we have already enough data to let us believe that LPS stimulation induce a downregulation of MDR - 1, and consequently Pgp, which could conduce to a prolonged retention of 99m Tc - Sestamibi in the inflamed cells . Conclusions: If and when this methodology demonstrate the promising results we expect, one will be able to con clude that Nuclear Medicine is an important tool to help evidence based research also on this specific field .

Genotoxic effects in occupational exposure to formaldehyde: A study in anatomy and pathology laboratories and formaldehyde-resins production

Background - According to the Report on Carcinogens, formaldehyde ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Given its economic importance and widespread use, many people are exposed to formaldehyde environmentally and/or occupationally. Presently, the International Agency for Research on Cancer classifies formaldehyde as carcinogenic to humans (Group 1), based on sufficient evidence in humans and in experimental animals. Manyfold in vitro studies clearly indicated that formaldehyde can induce genotoxic effects in proliferating cultured mammalian cells. Furthermore, some in vivo studies have found changes in epithelial cells and in peripheral blood lymphocytes related to formaldehyde exposure. Methods - A study was carried out in Portugal, using 80 workers occupationally exposed to formaldehyde vapours: 30 workers from formaldehyde and formaldehyde-based resins production factory and 50 from 10 pathology and anatomy laboratories. A control group of 85 non-exposed subjects was considered. Exposure assessment was performed by applying simultaneously two techniques of air monitoring: NIOSH Method 2541 and Photo Ionization Detection equipment with simultaneously video recording. Evaluation of genotoxic effects was performed by application of micronucleus test in exfoliated epithelial cells from buccal mucosa and peripheral blood lymphocytes. Results - Time-weighted average concentrations not exceeded the reference value (0.75 ppm) in the two occupational settings studied. Ceiling concentrations, on the other hand, were higher than reference value (0.3 ppm) in both. The frequency of micronucleus in peripheral blood lymphocytes and in epithelial cells was significantly higher in both exposed groups than in the control group (p < 0.001). Moreover, the frequency of micronucleus in peripheral blood lymphocytes was significantly higher in the laboratories group than in the factory workers (p < 0.05). A moderate positive correlation was found between duration of occupational exposure to formaldehyde (years of exposure) and micronucleus frequency in peripheral blood lymphocytes (r = 0.401; p < 0.001) and in epithelial cells (r = 0.209; p < 0.01). Conclusions - The population studied is exposed to high peak concentrations of formaldehyde with a long-term exposure. These two aspects, cumulatively, can be the cause of the observed genotoxic endpoint effects. The association of these cytogenetic effects with formaldehyde exposure gives important information to risk assessment process and may also be used to assess health risks for exposed workers.

Seroprevalence of human parvovirus B19 in a suburban population in São Paulo, Brazil

OBJECTIVE: To analyze the prevalence of IgG antibodies to human parvovirus B19. METHODS: Cross-sectional study in a suburban community in São Paulo, Southeastern Brazil, between November 1990 and January 1991. Randomly selected (N=435) representative samples of sera were collected from healthy children older than 15 days old and adults up to 40 years old. IgG antibodies were detected using ELISA. RESULTS: High prevalence of IgG antibodies to B19 parvovirus was found in 87% of newborns. The prevalence of maternally derived IgG antibodies exponentially plunged up to the 19th month of age. Low prevalence of antibodies was found in the first 4 years of life, increasing up to 72% in those aged 31-40 years. It was estimated that the average age of first infection in this population is 21 ± 7 years old and the optimal age for vaccination with a hypothetical vaccine would be 1 year of age. CONCLUSIONS: Parvovirus B19 IgG antibody prevalence was high in newborns and those aged 31-40 years. The analysis by age groups showed a pattern similar to that found in previous studies, i.e., low prevalence of infection in children that increases with age.

Immune responses in Bathymodiolus azoricus upon Vibrio challenges : approaches to characterize mussel survival strategies and physiological adaptations in deep sea extreme environments

Tese de Doutoramento, Ciências do Mar, especialidade de Biologia Marinha, 18 de Dezembro de 2015, Universidade dos Açores.

A aquisição de competências musicais no ensino da Técnica de Dança Clássica no 2º ano no Conservatório de Música da Jobra

Relatório Final de Estágio apresentado à Escola Superior de Dança, com vista à obtenção do grau de Mestre em Ensino de Dança.

Surfaces contamination with 5-Fluorouracil in two Portuguese hospitals

Background - The use of antineoplastic drugs in cancer therapy is increasing due to their action in cancer cells. Carcinogenic, mutagenic and teratogenic effects. Some studies demonstrated that nurses and pharmacy personnel involved in preparation or administration are exposed to antineoplastic drugs. Aim: assess 5-Fluorouracil (5-FU) contamination on the surfaces of two Portuguese Hospitals (preparation and administration units). 5-FU is one of the most frequently antineoplastic agent used in Portuguese Hospitals and can be easily absorbed through the skin. This drug can be used as an marker of surfaces contamination and exposure and have been extensively discussed in other studies.