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Pedro Moreira

Publications and source records attributed to Pedro Moreira.

14 recordsLinked to original sources
PubMed2006

Transcriptional and post-transcriptional regulation of retrotransposons IAP and MuERV-L affect pluripotency of mice ES cells.

BACKGROUND: In the mouse, culture of embryonic stem (ES) cells may decrease their pluripotency and give rise to foetal abnormalities in recipient embryos. These abnormalities are frequently associated with both, chromosome abnormalities or epigenetic alteration of imprinting genes; however, little is known about the epigenetic stability of endogenous retrotransposable elements (REs). In our laboratory, we came across a R1 ES cell line, which at passage 27, lost the ability of germline transmission and started inducing the kinky tail phenotype in all chimeric animals produced with it. METHODS: In order to investigate whether this phenotype was associated with chromosome alteration, inadvertent differentiation, or epigenetic modification, we characterized and compared this R1 ES cell line at passage 27 with an early passage and with a second ES cell line C57/CBAF1 generated in our laboratory. We assessed: i) karyotype; ii) expression of pluripotent and differentiation markers, iii) mRNA transcription by qRT-PCR of two REs, intracisternal-A particle (IAP) and murine endogenous-retrovirus-L (MuERV-L), and iv) methylation of IAP and MuERV-L. RESULTS: The R1 ES cell at passage 27, presented normal morphology, karyotype, and expression of genetic markers characteristic of pluripotent; however, it was detected an altered mRNA transcription of sense and antisense RNA strands of both REs, concomitantly with an altered methylation pattern for the IAP element but not for MuERV-L. These results indicate that besides methylation, other post-transcriptional processes are involved in gene silencing of some REs; and that culture of ES cells may decrease their pluripotency by producing inadvertent alterations in the expression of REs without significantly affecting the morphology, chromosome structure, and expression of pluripotent or differentiation markers. CONCLUSION: Inadvertent REs instability may have important consequences for the use of ES cells in transgenesis (chimera formation) or in cell therapy.

Animals↗
PubMed2006

Early identification of intensive care unit-acquired infections with daily monitoring of C-reactive protein: a prospective observational study.

INTRODUCTION: Manifestations of sepsis are sensitive but are poorly specific of infection. Our aim was to assess the value of daily measurements of C-reactive protein (CRP), temperature and white cell count (WCC) in the early identification of intensive care unit (ICU)-acquired infections. METHODS: We undertook a prospective observational cohort study (14 month). All patients admitted for > or =72 hours (n = 181) were divided into an infected (n = 35) and a noninfected group (n = 28). Infected patients had a documented ICU-acquired infection and were not receiving antibiotics for at least 5 days before diagnosis. Noninfected patients never received antibiotics and were discharged alive. The progression of CRP, temperature and WCC from day -5 to day 0 (day of infection diagnosis or of ICU discharge) was analyzed. Patients were divided into four patterns of CRP course according to a cutoff value for infection diagnosis of 8.7 mg/dl: pattern A, day 0 CRP >8.7 mg/dl and, in the previous days, at least once below the cutoff; pattern B, CRP always >8.7 mg/dl; pattern C, day 0 CRP < or =8.7 mg/dl and, in the previous days, at least once above the cutoff; and pattern D, CRP always < or =8.7 mg/dl. RESULTS: CRP and the temperature time-course showed a significant increase in infected patients, whereas in noninfected it remained almost unchanged (P < 0.001 and P < 0.001, respectively). The area under the curve for the maximum daily CRP variation in infection prediction was 0.86 (95% confidence interval: 0.752-0.933). A maximum daily CRP variation >4.1 mg/dl was a good marker of infection prediction (sensitivity 92.1%, specificity 71.4%), and in combination with a CRP concentration >8.7 mg/dl the discriminative power increased even further (sensitivity 92.1%, specificity 82.1%). Infection was diagnosed in 92% and 90% of patients with patterns A and B, respectively, and in only two patients with patterns C and D (P < 0.001). CONCLUSION: Daily CRP monitoring and the recognition of the CRP pattern could be useful in the prediction of ICU-acquired infections. Patients presenting maximum daily CRP variation >4.1 mg/dl plus a CRP level >8.7 mg/dl had an 88% risk of infection.

Adult↗
PubMed2005

[Effect of social desirability on dietary intake estimated from a food questionnaire].

INTRODUCTION: Self-report of dietary intake could be biased by social thus affecting risk estimates in epidemiological studies. The objective of study was to assess the effect of social desirability on dietary intake from a food frequency questionnaire (FFQ). METHODS: A convenience sample of 483 Portuguese university students was recruited. Subjects were invited to complete a two-part self-administered questionnaire: the first part included the Marlowe-Crowne Social Desirability Scale (M-CSDS), a physical activity questionnaire and self-reported height and weight; the second part, included a semi-quantitative FFQ validated for Portuguese adults, that should be returned after fulfillment. All subjects completed the first part of the questionnaire and 40.4% returned the FFQ fairly completed. RESULTS: In multiple regression analysis, after adjustment for energy and confounders, social desirability produced a significant positive effect in the estimates of dietary fibre, vitamin C, vitamin E, magnesium and potassium, in both genders. In multiple regression, after adjustment for energy and confounders, social desirability had a significant positive effect in the estimates of vegetable consumption, for both genders, and a negative effect in white bread and beer, for women. CONCLUSION: Social desirability affected nutritional and food intake estimated from a food frequency questionnaire.

Adult↗
PubMed2005

Educational, economic and dietary determinants of obesity in Portuguese adults: a cross-sectional study.

In industrialized countries, studies have shown that lower socioeconomic status is generally associated with higher rates of obesity. Furthermore, poorer eating habits with insufficient intake of low energy-dense and micronutrient rich foods may increase the risk of obesity. The aim of this study was to evaluate the importance of educational, economic and dietary factors in determining obesity risk in a representative sample of the Portuguese general adult population. Study design was cross-sectional in a representative sample of Portuguese adults (20,977 women and 18,663 men). Participants were distributed in categories according to years of education (< or =4, 5-9, 10-12, and >12), income (< or =314 euros, 315-547 euros, 548-815 euros, and >815 euros), and dietary intake (vegetable soup, vegetable, fruit, bread and starchy foods). Logistic regression models were fitted to estimate the magnitude of the association between obesity and education/income, and food groups, adjusting for confounders. In women and men, the odds favouring obesity decreased with increasing education (p-value for trend <0.001) being the odds ratios, respectively, 0.19 (0.14-0.27), and 0.40 (0.30-0.54) for those having >12 years of education compared to those with < or =4 years vegetable; soup consumption also decreased the risk of obesity in both genders (odds ratios were very similar in women and men, being respectively, 0.86 and 0.89). The odds favouring obesity in women also decreased with consumption of fruit and starchy foods, being the odds ratios, respectively, 0.77 (0.64-0.92), and 0.65 (0.55-0.78). In conclusion, educational attainment and vegetable intake decreased significantly the risk of obesity in Portuguese adults from both genders; fruits and starchy foods consumption also decreased the risk of obesity in women.

Adolescent↗
PubMed2005

Pilot study evaluating C-reactive protein levels in the assessment of response to treatment of severe bloodstream infection.

We evaluated the usefulness of monitoring daily C-reactive protein (CRP) levels after initiation of antimicrobial therapy in 44 patients with bloodstream infection. The ratio of the CRP level during therapy to the level at the start of antimicrobial therapy (CRP ratio) was measured. A CRP ratio of >0.58 at day 4 of therapy was a marker of poor outcome (sensitivity, 0.89; specificity, 0.69). The recognition of a pattern of CRP-ratio response was useful in the prediction of individual clinical course.

Anti-Bacterial Agents↗
PubMed2005

Prevalence and risk factors for overweight and obesity in Portuguese children.

AIM: To identify risk factors for overweight and obesity in Portuguese children. METHODS: A cross-sectional study of children 7 to 9.5 y old was performed between October 2002 and June 2003. A total of 2,274 girls and 2,237 boys were observed. Weight and height were measured, and parents filled out a questionnaire about family characteristics. Overweight and obesity, using age- and sex-specific body mass index (BMI) cut-off points as defined by the International Obesity Taskforce, were used. RESULTS: After adjustment for age and sex, the odds ratio for childhood obesity increased by television viewing (reference 0-2 h; 2-3 h: 1.51; 3-4 h: 1.72; 4 h: 1.63), paternal obesity (reference <18.5 kg/m(2); 25.0-29.9: 3.06; 30.0: 7.09), maternal obesity (reference <18.5 kg/m(2); 25.0-29.9: 9.06; 30.0: 18.13) and birthweight (reference <2,500 g; 2,500-3,000 g: 1.55; 3,000-3,500 g: 1.87; 3,500-4,000 g: 2.13; 4,000 g: 2.74), and decreased by sleeping duration (reference 8 h/d; 9-10 h/d: 0.44; 11 h/d: 0.39), paternal education (reference primary school; secondary: 0.91; university: 0.42), maternal education (reference primary school; secondary: 1.13; university: 0.56), being a single child (reference yes; no: 0.56) and family size (reference one child; two children: 0.59; three children: 0.44; more than four children: 0.37). CONCLUSION: Our data support the perspective that education about energy intake and energy expenditure should be used much earlier in those families with high-risk children, namely those with high parental BMI or high birthweight. Protective factors were parental education and family size.

Body Mass Index↗
PubMed2004

Relationship between non-return rate and chromatin condensation of deep frozen bull spermatozoa.

This study analyzes the relationship between chromatin condensation and field fertility, expressed as 90 days non-return rate (NRR), of bulls actively used by AI studs. Frozen-thawed semen from five bulls (six ejaculates per bull, three straws per ejaculate), that showed a non-return rate between 60 and 80%, were analyzed to assess sperm chromatin condensation and stability. The chromatin condensation was determined by flow cytometry using propidium iodide as fluorochrome, and the chromatin stability was evaluated by inducing its decondensation with SDS and EDTA. Coefficient of variation among replicates was less than 7% and 5% for chromatin condensation and stability, respectively. No correlation was present between chromatin condensation and NRR. However, significant correlation was found between chromatin stability and NRR. Chromatin stability was higher (P < 0.05) in those bulls that showed higher fertility. The results obtained in this study conclude that assessment of stability could be a valuable tool for routine evaluation and identification of ejaculates with high levels of sperm chromatin abnormalities and to detect animals of higher reproductive potential.

Animals↗
PubMed2004

[Body mass index: sensitivity and specificity].

INTRODUCTION: Self-reported height and weight data have been used in several studies with the purpose of determining the prevalence of overweight and obesity. Despite being a simple methodology, little information exists about the reliability of these measures, namely, in university students. The objective of this study was to determine the sensitivity and specificity of self-reported body mass index (BMI) to evaluate the prevalence of overweight and obesity in university students. METHODS: In a convenience sample of 380 university students (226 women and 154 men), weight and height were obtained by self-reported measures and anthropometric assessment according to international standards methodology (objective). BMI was calculated from self-reported and direct measures. RESULTS: The discrepancy between objective and self-reported weight was not significative. For height, this discrepancy was significantly different in women, in men, and between genders. The difference between BMI values was significantly different in women (0.8 +/- 1.1 kg/m2), in men (0.4 +/- 1.1 kg/m2) and between genders. Concerning overweight and obesity, according to the objective BMI, the sensitivity was only 50% in women, and 70% in men, while the specificity was 99% in women and 98% in men. CONCLUSION: Our results show a poor sensitivity of self-reported weight and height data, to estimate overweight and obesity, thus, this method might not be reliable for studies of prevalence of obesity in this population.

Adolescent↗
PubMed2004

Long-term effect of in vitro culture of mouse embryos with serum on mRNA expression of imprinting genes, development, and behavior.

The long-term developmental and behavioral consequences of mammalian embryo culture are unknown. By altering the culture medium with the addition of FCS, we wanted to determine whether mouse embryos cultured under suboptimal conditions develop aberrant mRNA expression of imprinting genes at the blastocyst stage and whether fetal development, growth, and behavior of adult mice are affected. One-cell embryos obtained from superovulated female B6CBAF(1) mice were cultured for 4 days in K(+)-modified simplex optimized medium in the presence of either 10% FCS or 1 g/liter BSA. After embryo transfer, born animals were submitted to several developmental and behavior tests. The mRNA expression of some imprinting genes was significantly affected in blastocysts cultured in the presence of FCS. Two of the eight measures of preweaning development and some specific measures of neuromotor development, such as the walking activity, were delayed in the group originated with FCS. After 34 weeks, the weight of female mice cultured in vitro in the presence of FCS was significantly higher than controls. In addition, the locomotion activity of mice was altered at 5 and 15 months. Anatomopathological and histological analysis of animals at 20 months of age showed some large organs and an increase in pathologies. We have found that mice derived from embryos cultured with FCS exhibited specific behavioral alterations in anxiety and displayed deficiencies in implicit memories. Our data indicate that long-term programming of postnatal development, growth, and physiology can be affected irreversibly during the preimplantation period of embryo development by suboptimal in vitro culture.

Animals↗
PubMed2004

Species-related differences in blastocyst quality are associated with differences in relative mRNA transcription.

The objective of this study was to compare the relative transcript abundance of several important candidate genes between ovine and bovine blastocysts. Blastocysts were produced by in vitro maturation, fertilization, and subsequent culture in one of two formulations of synthetic oviduct fluid medium (SOF1 and SOF2). From each IVF replicate groups of 10 bovine and 10 ovine blastocysts from each of the two media were used for analysis of mRNA relative abundance. Transcript levels for mitochondrial Mn-superoxide dismutase (MnSOD), survivin, and glucose transport 5 (Glut-5) were significantly higher in ovine blastocysts than bovine (P < 0.05), while transcripts for Connexin 31 (Cx31), interferon tau (IFN-tau), and sarcosine oxidase (SOX) were significantly more abundant in bovine blastocysts (P < 0.01). For the two remaining transcripts, E-cadherin (E-cad) and Na/K ATPase (Na/K), there was no difference. Culture of bovine embryos in SOF2 resulted in a significant increase in the level of expression of MnSOD and Glut-5 (P < 0.05) compared to those bovine embryos cultured in SOF1. For all the other transcripts, except survivin, there was a significant decrease in the relative abundance. Culture of sheep embryos in either SOF1 or SOF2 did not have a major influence on transcript abundance; of the eight transcripts examined, the relative abundance of only one, SOX, was significantly altered. Bovine blastocysts produced in SOF2 had significantly higher survival rates at 24, 48, and 72 hr and significantly higher hatching rates following vitrification and warming than those cultured in SOF1 (P < 0.001). In conclusion, we have quantified for the first time the mRNA expression of a set of important developmental genes in sheep blastocysts and we have demonstrated that these differences between species in their adaptability to culture conditions, manifested in differences in embryo morphology and cryotolerance, are related to differences in mRNA relative abundance. The results also highlight the usefulness of transcript analysis as a marker of embryo quality.

Animals↗
PubMed2003

[Validity assessment of a food frequency questionnaire by comparison with a 4-day diet record].

When dietary methods are used to evaluate nutritional intake, it is important to know which methods are most appropriate to ensure validity in nutrient intake studies. Our main objective was to assess the validity of a semi-quantitative food-frequency questionnaire (FFQ) developed for Portuguese adults by comparing nutrient intake (energy and 44 nutrients) assessed by FFQ with the nutritional data from a four-day diet record (DR). The FFQ was developed by the Epidemiology Department, Faculty of Medicine, University of Porto, and allowed the subjects to indicate their daily, weekly or monthly intake of 89 foods. Subjects were 246 university students (159 females and 87 males, aged 18 to 29 years). Mean intakes from the FFQ were generally higher than those from the DR. Pearson correlation coefficients between FFQ and DR ranged from 0.21 for vitamin D, to 0.73, for iodine. When energy-adjusted, this coefficients ranged from 0.20, for selenium, to 0.75 for iodine. Misclassification in opposite extreme quintiles varied from 0% to 16%, and the proportion of subjects correctly classified within the lowest two quintiles ranged between 52% and 84%. The distribution of those correctly classified within the highest two quintiles ranged between 51% and 88%. Exact classification in the same quintile of ingestion varied from 26% and 41%. These data suggest that this FFQ provides valid estimates of intakes for major nutrients, comparable to those reported from other studies in the literature.

Adult↗
PubMed2003

Hyperglycemia-induced apoptosis affects sex ratio of bovine and murine preimplantation embryos.

The effect of glucose in the medium used during in vitro culture on both cell death by apoptosis and the sex ratio of bovine blastocysts derived from in vitro-matured and in vitro-fertilized oocytes was evaluated. Oocytes were matured, inseminated, and cultured in vitro in mSOF medium with 10% FCS with or without glucose supplementation. Exposure to high concentrations of glucose (10, 20, and 30 mM) during bovine embryo development in vitro from zygote to blastocyst resulted in a decrease in the number of cells per embryo and an increase in the frequency of apoptotic cells. A significantly higher proportion of females was found among those embryos that developed under hyperglycemic conditions in vitro. Moreover, both murine and bovine blastocysts incubated for 6 hr in 20 mM glucose had a significantly higher number of apoptotic cells in comparison to control. In this study, we also determined whether blastocyst production of the X-linked inhibitor of apoptosis protein (XIAP) differs between the sexes. Our results show that female bovine blastocysts produce significantly higher amounts of XIAP mRNA than males and this could be crucial in explaining the higher proportion of female blastocysts observed following in vitro culture under hyperglycemic conditions which induce apoptosis. Moreover, a higher proportion of female murine blastocysts cultured under hyperglycemic conditions were implanted in the uterus (65.3 of implantations from embryos cultured with 20 mM of glucose are females vs. 49% in control). This mechanism provides an explanation for the significant reduction of male children born to diabetic mothers.

Animals↗
PubMed2002

Differential regulation of maternal and paternal chromosome condensation in mitotic zygotes.

A-kinase anchoring protein AKAP95 is implicated in somatic mitotic chromosome condensation by recruiting the condensin complex. Here, we report a differential regulation of condensation of maternal and paternal chromosomes mediated by AKAP95 in mitotic mouse zygotes. AKAP95 is synthesized upon oocyte activation, targeted to the female pronucleus and specifically associates with maternal chromosomes at mitosis. AKAP95 mRNA is highly restricted to the vicinity of the meiotic spindle in metaphase II oocytes. In vivo displacement of endogenous AKAP95 in female pronuclei by microinjection of competitor peptides and rescue experiments show that AKPA95 is required for recruitment of the mCAP-D2 condensin subunit to, and condensation of, maternal chromosomes. In contrast, AKAP95 is dispensable for mCAP-D2 recruitment to, and condensation of, paternal chromosomes. Our results indicate that at first embryonic mitosis, paternal chromosomes target condensins and condense independently of AKAP95, whereas maternal chromosomes require AKAP95 for condensin recruitment and condensation. We propose a concept whereby condensation of chromosomes in gametes, zygotes and somatic cells involves related but distinct mechanisms.

Adenosine Triphosphatases↗