Improving chitosan-mediated gene transfer by the introduction of intracellular buffering moieties into the chitosan backbone

Chitosan was functionalized with imidazole moieties (CHimi) with the aim of improving its buffering capacity and promoting the endosomal escape ability of chitosan-DNA complexes, ultimately increasing their transfection efficiency. 5.6%, 12.9% and 22.1% of the glucosamine residues of chitosan were substituted. Complexes with different molar ratios of primary amines to DNA phosphate anion (N/P) were prepared by a coacervation method. For an N/P>3, CHimi polymers are able to complex electrostatically with DNA and condense it into positively charged nanostructures (average size 260 nm and zeta potential +16 mV at pH 5.5). In the concentration range 2.5-100 microg ml(-1), the modified polymers had no cytotoxic effect on 293T cells. CHimi polymers with the highest degree of substitution were found to enhance beta-gal expression in 293T and HepG2 cells. Bafilomycin A1 inhibited transfection, indicating that the protonation of the imidazole groups in the endolysosome pathway favors the escape of the complexes from the endosomes, increasing the amount of transgene that can reach the cell nucleus.

The independent associations of sedentary behaviour and physical activity on cardiorespiratory fitness

BACKGROUND

During childhood and adolescence, both physical activity (PA) and sedentary behaviour seem to influence cardiorespiratory fitness (CRF); however, the combined association of PA and sedentary behaviour remains to be understood. We analysed the combined association of objectively measured sedentary behaviour and moderate-to-vigorous intensity PA (MVPA) on CRF in Portuguese children and adolescents.

METHODS

The sample comprised 2506 Portuguese healthy children and adolescents aged 10-18 years, from a cross-sectional school-based study (2008). PA and sedentary behaviour were assessed with accelerometry. Participants were classified as meeting current PA guidelines for youth versus not meeting, and as low versus high sedentary (according to the median value of sedentary time/day by age and gender), and then grouped as follows: Low active-high sedentary; low active-low sedentary; high active-high sedentary; high active-low sedentary. CRF was assessed with the FITNESSGRAM 20 m shuttle-run test. Binary logistic regression models were constructed to verify the relationship between high CRF and the combined influence of MVPA/sedentary behaviour, adjusting for age, gender, body mass index and accelerometer wear time.

RESULTS

Participants classified as high active/low sedentary (OR=1.81; 95% CI 1.21 to 2.69), as well as those classified as low active/low sedentary (OR=1.27; 95% CI 1.01 to 1.61) were more likely to be fit, compared with those from the low-active/high-sedentary group.

CONCLUSION

MVPA and sedentary behaviour may act independently in their relation with CRF, and that MVPA levels may not overcome the deleterious influence of high-sedentary time in maximising CRF.

The Effects of Workplace Physical Activity Programs on Musculoskeletal Pain: A Systematic Review and Meta-Analysis

This article reviews the effectiveness of physical activity (PA) interventions at the workplace to reduce musculoskeletal pain among employees and assesses the effect size of these programs using meta-analysis. Four databases (i.e., PubMed, EBSCO, Web of Science, and Cochrane) were searched for research trials, which included comparison groups of employees that assessed PA programs, musculoskeletal pain, and health-related behaviors, published between January 1990 and March 2013. The meta-analysis estimates of standardized mean differences (Hedges' g) present significant evidence of less general pain (g = -.40 with a 95% confidence interval [CI] = [-0.78, -0.02]) and neck and shoulder pain (g = -.37 with a 95% CI = [-0.63, -0.12]) in intervention groups. The few studies of low back pain and arm, elbow, wrist, hand, or finger pain did not present sufficient statistically significant evidence. Consistent evidence demonstrates that workplace PA interventions significantly reduce general musculoskeletal pain and neck and shoulder pain. More studies are needed to determine the effectiveness of work-related PA interventions for arm, elbow, wrist, hand or finger, and low back pain.

Tepidimonas ignava gen. nov., sp. nov., a new chemolithoheterotrophic and slightly thermophilic member of the beta-Proteobacteria

A bacterial isolate with an optimum growth temperature of about 55 degrees C was recovered on a medium composed of one part Kligler's iron agar and four parts of Thermus Agar from the host spring at São Pedro do Sul in central Portugal. Phylogenetic analyses using the 16S rRNA gene sequence of strain SPS-1037T indicated that the new organism represented a new genus and species of beta-Proteobacteria. The major fatty acids of strain SPS-1037T are C16:0 and C17:0. Ubiquinone 8 is the major respiratory quinone, and the major polar lipids are phosphatidylethanolamine and phosphatidylglycerol. The new isolate is aerobic and chemolithoheterotrophic. Thiosulfate and tetrathionate were oxidized to sulfate. The growth yield of the organism was improved by the addition of thiosulfate to media containing organic carbon sources, but the organism did not grow autotrophically under the conditions examined. Heterotrophic growth of strain SPS-1037T occurs on amino acids and organic acids, but this organism does not assimilate carbohydrates. On the basis of the phylogenetic analyses, and physiological and biochemical characteristics, it is proposed that strain SPS-1037T represents a new genus and a new species for which the name Tepidimonas ignava is proposed.

Associations between physical fitness and adherence to the Mediterranean diet with health-related quality of life in adolescents: results from the LabMed Physical Activity Study

Background

Physical fitness (PF) and adherence to the Mediterranean diet are important indicators of healthy lifestyles. The purpose of this study is to analyze the independent and combined associations between PF and adherence to Mediterranean diet with health-related quality of life (HRQoL) in adolescents.

Methods

This is a cross-sectional analysis with 956 Portuguese adolescents aged 12-18 years. HRQoL was measured with the Kidscreen-10 questionnaire. PF was assessed with the ALPHA health-related fitness battery. The 20-m shuttle run test was used for the estimation of cardiorespiratory fitness; handgrip strength and standing long jump tests were applied for the assessment of muscular fitness and the 4 × 10 m shuttle run test for the assessment of motor fitness (speed and agility). The results of the PF tests (cardiorespiratory fitness, muscular fitness and motor fitness) were transformed into standardized values (Z-scores) by age and sex. Adherence to the Mediterranean diet was assessed with the KIDMED index. Regression analysis and analysis of covariance were performed.

Results

PF (B = 0.228; P < 0.05) and adherence to the Mediterranean diet (B = 0.259; P < 0.05) were positively associated with HRQoL, after controlling for several variables. Participants classified as high PF and high adherence to Mediterranean diet had on average the highest HRQoL score compared with those with low PF and low adherence to Mediterranean diet (F(3, 939) = 4.270; P = 0.005), after adjustments for potential confounders.

Conclusions

The combination of high PF levels and optimal adherence to Mediterranean diet is positively associated with HRQoL.

3-D volume rendering maxillofacial analysis of angular measurements by multislice CT

OBJECTIVE

This study was designed to determine the precision and accuracy of angular measurements using three-dimensional computed tomography (3D-CT) volume rendering by computer systems.

STUDY DESIGN

The study population consisted of 28 dried skulls that were scanned with a 64-row multislice CT, and 3D-CT images were generated. Angular measurements, (n = 6) based upon conventional craniometric anatomical landmarks (n = 9), were identified independently in 3D-CT images by 2 radiologists, twice each, and were then performed by 3D-CT imaging. Subsequently, physical measurements were made by a third examiner using a Beyond Crysta-C9168 series 900 device.

RESULTS

The results demonstrated no statistically significant difference between interexaminer and intraexaminer analysis. The mean difference between the physical and 3-D-based angular measurements was -1.18% and -0.89%, respectively, for both examiners, demonstrating high accuracy.

CONCLUSION

Maxillofacial analysis of angular measurements using 3D-CT volume rendering by 64-row multislice CT is established and can be used for orthodontic and dentofacial orthopedic applications.

Prevalence and incidence of cognitive impairment in an elder Portuguese population (65-85 years old)

BACKGROUND

The increase in average life expectancy increases the risk of illness and frailty in the elderly, especially in the cognitive arena. This study has the objective to estimate the prevalence and incidence of cognitive impairment, in a representative sample of 65 to 85 years old followed for a mean period of 6-years.

METHODS

Subjects aged 65-85 years (n = 586) were screened at baseline (1999-2004) to estimate the prevalence of cognitive impairment using the Mini-Mental State Examination. A total of 287 individuals with a normal MMSE at baseline were reassessed after 6.2 mean years (± 4.30 years) to evaluate the incidence of cognitive impairment, defined as scoring below the age and education-adjusted MMSE cut-off points adapted for the Portuguese population. We did not exclude Dementia.

RESULTS

The baseline prevalence of cognitive impairment was 15.5% (95% CI: 12.7-18.7). Higher in women (18.9%; 95% CI: 14.9-23.3), that in men (10.4%; 95% CI: 6.7-15.1). Increased with age and was highest for participants without any schooling. The overall incidence rate was 26.97 per 1000 person-years; higher in women (33.8 per 1000 person-years) than in men (18.0 per 1000 person-years). Higher for the oldest participants and those with no schooling. Taking the standard European population, we estimated a prevalence of 16.5% and an incidence of 34.4 per 1000 person-years.

CONCLUSION

The prevalence of cognitive impairment in Portugal is within the estimated interval for the European population, and the incidence is lower than for the majority of the European countries. Women, senior and elders without education have a higher risk of cognitive impairment. In our sample, neither employment nor marital status has a significant effect on cognitive impairment.

Muscular fitness and cardiorespiratory fitness are associated with health-related quality of life: Results from labmed physical activity study

BACKGROUND

Adolescents' physical fitness levels are an important indicator of their lifestyle and seem to have positive consequences in health-related quality of life (HRQoL).

OBJECTIVE

The purpose of this study is to analyse the combined associations of cardiorespiratory fitness and muscular fitness with HRQoL and to assess the differences between HRQoL scores across groups of cardiorespiratory fitness and muscular fitness in Portuguese adolescents.

DESIGN

This is a cross-sectional analysis with 567 Portuguese adolescents aged 12-18 years-old.

METHODS

HRQoL was measured using the Kidscreen-10 questionnaire. Cardiorespiratory fitness was estimated with the 20-m shuttle-run test. Muscular fitness was evaluated using the handgrip and the standing long jump tests and a muscular fitness index was computed by means of standardized measures of both tests. Socioeconomic status was assessed using the Family Affluence Scale. Body composition (body mass and height) was measured according to standard protocols. Accelerometers were used to obtain objective physical activity time. Pubertal stage was assessed using Tanner stages. Adherence to the Mediterranean diet was assessed using the KIDMED index. Participants were divided into four groups based on low or high values of both cardiorespiratory and muscular fitness. Regression analysis, mediation analysis and ANCOVA were performed.

RESULTS

HRQoL was positively associated with cardiorespiratory fitness (B = 0.112; p < 0.05) and muscular fitness score (B = 0.328 p < 0.05), after controlling for potential confounders. However, when both fitness variables were entered in the same model only cardiorespiratory fitness remained significantly associated with HRQoL (B = 0.093 p < 0.05). Cardiorespiratory fitness acted as a full mediator variable on the relationship between muscular fitness and HRQoL in adolescents (p < 0.05). ANCOVA showed that adolescents with high cardiorespiratory fitness/high muscular fitness exhibit better HRQoL scores when compared to those with low muscular fitness/low cardiorespiratory fitness and with those with low muscular fitness/high cardiorespiratory fitness (p < 0.05).

CONCLUSIONS

In adolescents, the combination of high cardiorespiratory fitness and high muscular fitness was positively associated with a better HRQoL.

Metabolic syndrome, physical activity and cardiac autonomic function

BACKGROUND

Our primary aim was to investigate the associations that components of metabolic syndrome and physical activity have with cardiac autonomic nervous system activity as estimated by heart rate variability (HRV) in young adults free of metabolic abnormalities. We also aimed to identify predictors of 3-year changes in HRV.

METHODS

Physical activity was assessed annually in 163 healthy participants over 3 years (2008-2010). Components of metabolic syndrome measured annually were; waist circumference, systolic blood pressure, high-density lipoprotein, triglycerides, glucose, and C-reactive protein. A linear mixed regression model was used to assess associations between HRV, metabolic syndrome components and physical activity. Linear regression was used to identify predictors of changes in HRV.

RESULTS

 Metabolic syndrome components were negatively associated with HRV indices and higher heart rate, while physical activity was associated with higher HRV and lower heart rate. Physical activity and inflammation were predictors of positive and negative changes in HRV indices, respectively.

CONCLUSIONS

 In participants without significant metabolic abnormalities, metabolic syndrome components were still associated with less favourable HRV profiles. Physical activity and inflammation were both able to predict changes in HRV, albeit in different directions. It appears that the process of autonomic dysfunction starts at a young age and may be mediated in part by inflammation. Metabolic syndrome prevalence is increasing in younger populations; promoting the metabolic and autonomic benefits of exercise remains imperative.

Cardiorespiratory Fitness and Blood Pressure: A Longitudinal Analysis

OBJECTIVES

To examine the association between cardiorespiratory fitness and cardiovascular indices 2 years later, and to determine whether changes in cardiorespiratory fitness are associated with cardiovascular indices at a 2-year follow-up in adolescents.

STUDY DESIGN

The sample comprised 734 adolescents (349 girls) aged 12-18 years followed for 3 years from the LabMed Physical Activity Study. Cardiorespiratory fitness was assessed by the 20-meter shuttle run test. Height, weight, waist circumference, and resting blood pressure (BP) were measured according to standard procedures.

RESULTS

Regression analyses showed a significant inverse association between cardiorespiratory fitness at baseline and systolic BP (B = -0.126; P = .047) and rate pressure product (B = -29.94; P = .016), at follow-up after adjustments for age, sex, height, pubertal stage, socioeconomic status, and waist circumference. Significant differences were found between cardiorespiratory fitness groups (fit vs unfit) at baseline and systolic BP and rate pressure product at follow-up (P < .05 for all). Analysis of covariance showed a significant association between cardiorespiratory fitness changes and systolic BP (P = .024) and rate pressure product (P = .014), after adjustment for age, sex, height, pubertal status, socioeconomic status, and waist circumference.

CONCLUSIONS

Changes in cardiorespiratory fitness during adolescence were associated with cardiovascular indices over a 2-year period. Adolescents with persistently low levels of cardiorespiratory fitness exhibited the highest levels of systolic BP and rate pressure product.

Association between serum adiponectin levels and muscular fitness in Portuguese adolescents: LabMed Physical Activity Study

BACKGROUND AND AIM

Paradoxically, recent investigations have showed that adiponectin levels are inversely associated with muscle strength. However, to date, there is a lack of knowledge on the relationship between muscular fitness (MF) and adiponectin levels in adolescents. We aimed to examine the independent associations between MF and adiponectin levels in adolescents, controlling for several potential confounders.

METHODS AND RESULTS

This is a cross-sectional analysis with 529 Portuguese adolescents aged 12-18 years. A MF score was computed as the mean of the handgrip strength and standing long jump standardized values by age and gender. We measured fasting glucose, insulin, HDL-cholesterol, C-reactive protein and adiponectin. Linear regression analysis showed a significant inverse association between adiponectin (Z-score by age and sex) and MF score, after adjustments for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, body mass index, HOMA-IR, HDL-cholesterol, C-reactive protein and cardiorespiratory fitness (unstandardized β = -0.176; p < 0.005). Analysis of covariance showed a significant difference between the Low MF/Non-overweight group and the High MF/Non-overweight Group (p < 0.05) and between the Low MF/Non-overweight and High MF/Overweight Group (p < 0.05) (F (5, 523) = 2.262, p = 0.047).

CONCLUSION

Adiponectin circulating levels are inversely and independently associated with MF. In non-overweight adolescents, those with high levels of MF presented lower levels of adiponectin compared to those with Low MF. Likewise, overweight adolescents with High MF presented lower levels of serum adiponectin than non-overweight adolescents with Low MF.

The barium enema in constipation: comparison with rectal manometry and biopsy to exclude Hirschsprung's disease after the neonatal period

BACKGROUND

The diagnosis of Hirschsprung's disease is usually made in neonates but often considered in older infants and children with constipation: these children may be referred for barium enema. Since it is widely accepted that a normal barium enema does not exclude Hirschsprung's disease, some children, after a normal enema, undergo more invasive procedures such as rectal manometry or biopsy. Our study asked how frequently a diagnosis of Hirschsprung's disease was made by biopsy or manometry in children who had normal barium enema.

MATERIALS AND METHODS

We reviewed the medical records and barium enemas of 54 patients older than 28 days with constipation or difficulty passing stool who had a barium enema followed by manometry and/or biopsy.

RESULTS

Forty-eight patients had normal enemas: 24 of those patients had biopsies, 16 had manometry, and 8 both manometry and biopsy. Only 1 had manometry suggestive of Hirschsprung's disease, confirmed by biopsy. Six patients had abnormal enemas. Five had biopsy and manometry compatible with Hirschsprung's disease; one had a normal biopsy and manometry study.

CONCLUSION

The barium enema is a good initial screening test for Hirschsprung's disease in severely constipated children since it correlates well with manometry and biopsy. The enema is particularly useful in centers without easy access to pediatric gastroenterology services, and a normal enema in this setting allows the continuation of medical therapy with further evaluation only if there is a lack of response. An abnormal enema, however, requires referral to a facility equipped to perform confirmatory manometry or biopsy.

Inverse agonism and constitutive activity as functional correlates of serotonin h5-HT(1B) receptor/G-protein stoichiometry

This study evaluated the influence of receptor/G-protein (R:G) stoichiometry on constitutive activity and the efficacy of agonists, partial agonists, and inverse agonists at human (h) 5-hydroxytryphamine 1B (5-HT(1B)) receptors. Two Chinese hamster ovary cell lines were used; they expressed 8.5 versus 0.4 pmol h5-HT(1B) receptors/mg (determined by [(3)H]GR125,743 saturation analysis) and 3.0 versus 1.5 pmol receptor-activated G-proteins/mg [determined by guanosine-5'-O-(3-[(35)S]thio)-triphosphate ([(35)S]GTPgammaS) isotopic dilution], respectively. Thus, they displayed R:G ratios of approximately 3.0 (RGhigh) and approximately 0.3 (RGlow), respectively. In competition-binding experiments, the agonists, 5-HT and sumatriptan, displayed fewer high-affinity (HA)-binding sites and the partial agonists, BMS181, 101 and L775,606, displayed decreased affinity in RGhigh versus RGlow membranes. In contrast, the inverse agonists, SB224,289 and, to a lesser extent, methiothepin, showed increased affinity. In G-protein activation experiments, both basal and 5-HT-activated [(35)S]GTPgammaS binding were higher in RGhigh than in RGlow membranes. Constitutive activity (determined by inhibition of basal [(35)S]GTPgammaS binding with GTPgammaS in the absence of receptor ligands) was more pronounced in RGhigh versus RGlow membranes, as revealed by the >5-fold greater proportion of HA sites. Correspondingly, the negative efficacy of inverse agonists was strikingly augmented, inasmuch as they suppressed approximately two-thirds of HA [(35)S]GTPgammaS binding in RGhigh membranes, but only approximately one-third in RGlow membranes. Furthermore, the efficacy of partial agonists was greater at RGhigh versus RGlow membranes, as estimated by their ability to enhance [(35)S]GTPgammaS binding. In conclusion, an increase in R:G ratios at h5-HT(1B) receptors was associated with an increase in relative efficacy of partial agonists and, most notably, an increase in both constitutive G-protein activation and negative efficacy of inverse agonists.

Intake of milk, but not total dairy, yogurt, or cheese, is negatively associated with the clustering of cardiometabolic risk factors in adolescents

Epidemiologic studies have reported an inverse association between dairy product consumption and cardiometabolic risk factors in adults, but this relation is relatively unexplored in adolescents. We hypothesized that a higher dairy product intake is associated with lower cardiometabolic risk factor clustering in adolescents. To test this hypothesis, a cross-sectional study was conducted with 494 adolescents aged 15 to 18 years from the Azorean Archipelago, Portugal. We measured fasting glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, systolic blood pressure, body fat, and cardiorespiratory fitness. We also calculated homeostatic model assessment and total cholesterol/high-density lipoprotein cholesterol ratio. For each one of these variables, a z score was computed using age and sex. A cardiometabolic risk score (CMRS) was constructed by summing up the z scores of all individual risk factors. High risk was considered to exist when an individual had at least 1 SD from this score. Diet was evaluated using a food frequency questionnaire, and the intake of total dairy (included milk, yogurt, and cheese), milk, yogurt, and cheese was categorized as low (equal to or below the median of the total sample) or "appropriate" (above the median of the total sample).The association between dairy product intake and CMRS was evaluated using separate logistic regression, and the results were adjusted for confounders. Adolescents with high milk intake had lower CMRS, compared with those with low intake (10.6% vs 18.1%, P = .018). Adolescents with appropriate milk intake were less likely to have high CMRS than those with low milk intake (odds ratio, 0.531; 95% confidence interval, 0.302-0.931). No association was found between CMRS and total dairy, yogurt, and cheese intake. Only milk intake seems to be inversely related to CMRS in adolescents.

Interval breast cancers in New South Wales, Australia, and comparisons with trials and other mammographic screening programmes

OBJECTIVE

To present information on 1st year interval breast cancer from the New South Wales mammographic screening programme and to compare with published results from trials and services.

SETTING

New South Wales data were derived from a population based biennial mammographic screening programme, which achieved statewide coverage in 1995. Women aged 50-69 years screened during 1995-7 were included.

METHODS

Bilateral two view mammography with reading by two radiologists is used for biennial screening examinations. Interval cancers were detected by the screening programme and by linkage with the statewide cancer registry. In situ carcinoma was excluded. Incidence of interval cancer was estimated as a proportion of the expected underlying incidence of breast cancer. Comparative data were derived from the published literature and meta-analyses were performed.

RESULTS

Although randomised trials of screening have a proportional incidence by meta-analysis of 19% (95% confidence interval (95% CI) 12% to 25%), service studies yield a proportional incidence by meta-analysis of 27% (95% CI 25% to 30%), and more than half report proportional incidences greater than 25%. In the New South Wales mammographic screening programme the proportional incidence of interval breast cancer was 33% (95% CI 29% to 38%) for ages 50-59 years, 28% (95% CI 24% to 32%) for ages 60-69 years, and 31% (95% CI 28% to 34%) for ages 50-69 years combined. Proportional incidence in the New South Wales programme for ages 50-69 years was not significantly different from the rate for service studies by meta-analysis.

CONCLUSIONS

Effectiveness of mammographic screening for reducing mortality from breast cancer needs to be examined relative to rates of interval cancer from actual service situations as trials may concentrate resources and expertise in ways which may be less replicable in routine delivery of the service.

Milk intake is inversely related to body mass index and body fat in girls

Dairy foods comprise a range of products with varying nutritional content. The intake of dairy products (DPs) has been shown to have beneficial effects on body weight and body fat. This study aimed to examine the independent association between DP intake, body mass index (BMI), and percentage body fat (%BF) in adolescents. A cross-sectional, school-based study was conducted with 1,001 adolescents (418 boys), ages 15-18 years, from the Azorean Archipelago, Portugal. Anthropometric measurements were recorded (weight and height), and %BF was assessed using bioelectric impedance analysis. Adolescent food intake was measured using a self-administered, semiquantitative food frequency questionnaire. Data were analyzed separately for girls and boys, and separate multiple linear regression analysis was used to estimate the association between total DP, milk, yogurt, and cheese intake, BMI, and %BF, adjusting for potential confounders. For boys and girls, respectively, total DP consumption was 2.6 ± 1.9 and 2.9 ± 2.5 servings/day (P = 0.004), while milk consumption was 1.7 ± 1.4 and 2.0 ± 1.7 servings/day (P = 0.001), yogurt consumption was 0.5 ± 0.6 and 0.4 ± 0.7 servings/day (P = 0.247), and cheese consumption was 0.4 ± 0.6 and 0.5 ± 0.8 servings/day (P = 0.081). After adjusting for age, birth weight, energy intake, protein, total fat, sugar, dietary fiber, total calcium intake, low-energy reporters, parental education, pubertal stage, and physical activity, only milk intake was negatively associated with BMI and %BF in girls (respectively, girls: β = -0.167, P = 0.013; boys: β = -0.019, P = 0.824 and girls: β = -0.143, P = 0.030; boys: β = -0.051, P = 0.548).

CONCLUSION

We found an inverse association between milk intake and both BMI and %BF only in girls.

Physical Activity Patterns During Pregnancy in a Sample of Portuguese Women: A Longitudinal Prospective Study

BACKGROUND

Physical activity (PA) patterns during pregnancy have not been explored in depth and most previous studies lack assessment of variables such as type, frequency, duration and intensity of activity.

OBJECTIVES

This study had two goals: 1) to analyze PA patterns during pregnancy according to weekly time spent on different types of activity; and 2) to determine women's perception about health care providers regarding PA advisement during pregnancy.

PATIENTS AND METHODS

A longitudinal prospective study was carried out with a 118-pregnant women cohort. Participants were evaluated during all trimesters. Self-reported questionnaires were used to collect personal and obstetric data. Type, duration and frequency of PA were evaluated using the pregnancy physical activity questionnaire (PPAQ) and intensity levels were calculated. Repeated measure analysis of variance was performed to determine differences between trimesters, and Wilcoxon signed-rank test was performed when appropriate.

RESULTS

A decrease in values of self-reported PA (MET.h.wk(-1)) was found from the first to the second and the first to the third trimester of pregnancy, respectively; total (270.91 vs 220.54 vs 210.35; P < 0.01), light (109.45 vs 95.11vs 92.40; P < 0.01) and moderate intensity (81.99 vs 50.69 vs 62.94; P = 0.002). Time spent on most activities remained fairly stable throughout pregnancy. Women spent most of their weekly time during the entire pregnancy on household and caregiving activities, occupational activities and leisure, except sport activities. Swimming was the most reported organized PA, reaching its highest proportion (12.7%) in the second trimester. Prenatal exercise classes were reported by 39.8% of women during the 3rd trimester. Pregnant women reported that PA was recommended by health professionals: 53.9% in the 1st trimester, 70.4% in the 2nd trimester and 56.8% in the 3rd trimester.

CONCLUSIONS

Self-reported PA decreased, especially from the first to the second trimester, in total, light and moderate intensity. Women spent most of their weekly time on domestic, occupational and leisure activities, except sport activities. There are some health care providers that do not recommend physical activity during pregnancy.

A semiparametric estimator of survival for doubly truncated data

Doubly truncated data are often encountered in the analysis of survival times, when the sample reduces to those individuals with terminating event falling on a given observational window. In this paper we assume that some information about the bivariate distribution function (df) of the truncation times is available. More specifically, we represent this information by means of a parametric model for the joint df of the truncation times. Under this assumption, a new semiparametric estimator of the lifetime df is derived. We obtain asymptotic results for the new estimator, and we show in simulations that it may be more efficient than the Efron-Petrosian nonparametric maximum likelihood estimator. Data on the age at diagnosis of childhood cancer in North Portugal are analyzed with the new method.

Metabolic risk factors, physical activity and physical fitness in Azorean adolescents: a cross-sectional study

Background

The prevalence of metabolic syndrome has increased over the last few decades in adolescents and has become an important health challenge worldwide. This study analyzed the relationships between metabolic risk factors (MRF) and physical activity (PA) and physical fitness (PF) in a sample of Azorean adolescents.

Methods

A cross-sectional school-based study was conducted on 417 adolescents (243 girls) aged 15-18 from the Azorean Islands, Portugal. Height, weight, waist circumference, fasting glucose, HDL-cholesterol, triglycerides, and blood pressure were measured. A sum of MRF was computed, and adolescents were classified into three groups: no MRF, one MRF and two or more MRF. PA was assessed by a sealed pedometer. PF was assessed using five tests from the Fitnessgram Test Battery. Dietary intake was obtained using a semi-quantitative food frequency questionnaire.

Results

Mean daily steps for girls and boys were 7427 ± 2725 and 7916 ± 3936, respectively. Fifty-nine percent of the adolescents showed at least one MRF and 57.6% were under the healthy zone in the 20 m Shuttle Run Test. Ordinal logistic regression analysis showed that after adjusting for sex, body mass index, socio-economic status and adherence to a Mediterranean diet, adolescents who were in the highest quartile of the pedometer step/counts (≥9423 steps/day) and those who achieved the healthy zone in five tests were less likely to have one or more MRF (OR = 0.56;95%CI:0.33-0.95; OR = 0.55;95%CI:0.31-0.98, respectively).

Conclusions

Daily step counts and PF levels were negatively associated with having one or more MRF among Azorean adolescents. Our findings emphasize the importance of promoting and increasing regular PA and PF to reduce the public health burden of chronic diseases associated with a sedentary lifestyle.

Stimulation of heparan sulfate proteoglycan synthesis and secretion during G1 phase induced by growth factors and PMA

Fetal calf serum (FCS) and PMA (phorbol 12-myristate-13-acetate) specifically stimulate the synthesis of heparan sulfate proteoglycan in endothelial cells. Staurosporine and n-butanol, kinase inhibitors, abolish the PMA effect. Forskolin and 8-bromo adenosine 3':5'-cyclic monophosphate, activators of, respectively, adenylate cyclase and protein kinase A cannot reproduce the PMA effect. The kinetics of cell entry into S phase of the endothelial cells was determined by DNA synthesis ([3H]-thymidine and Br-dU incorporation), and flow cytometry. The mitogenic effect of fetal calf serum is abolished by PMA. Also, PMA pre-treatment inhibits the enhanced synthesis of heparan sulfate proteoglycan after a second PMA exposure. Remarkably, the stimulation of heparan sulfate proteoglycan synthesis by fetal calf serum and PMA seems to be mainly restricted to G1 phase. Therefore fetal calf serum and PMA cause an enhanced synthesis of heparan sulfate proteoglycan, and PMA causes a cell cycle block at G1 phase.

Ability of Measures of Adiposity in Identifying Adverse Levels of Inflammatory and Metabolic Markers in Adolescents

BACKGROUND

Overweight and obesity have been associated with a pro-inflammatory state. We aimed to assess the ability of different measures of overall and abdominal adiposity for identifying adverse levels of inflammatory and metabolic markers in adolescents.

METHODS

This is a cross-sectional analysis with 529 Portuguese adolescents (267 girls), mean age 14.3 ± 1.7 years. Weight, height, sitting height, waist circumference (WC), and body fat percentage (BF%) were measured; and BMI, waist-to-height ratio (WHtR), and waist-to-sitting-height ratio (WsHtR) were calculated. We measured C-reactive protein (CRP), fibrinogen, erythrocyte sedimentation rate (ESR), complements C3 and C4, leptin, and adiponectin levels. Receiver operating characteristic (ROC) curves were used to estimate the ability of the adiposity measures to discriminate between low/high values of biomarkers.

RESULTS

The highest areas under the ROC curves were presented by BF% for fibrinogen and complement C3 in both sexes and for ESR, complement C4, and adiponectin only in girls; by BMI for CRP in girls and for leptin in both sexes; by WHtR for leptin in both sexes and for CRP, fibrinogen, and adiponectin only in girls; by waist circumference for CRP, fibrinogen, and complement C3 only in boys and for complement C4 in girls; and by WsHtR for complement C3 in girls; p < 0.05 for all.

CONCLUSIONS

The measures that more often presented discriminatory power were, for overall adiposity, BF% in both sexes, and for abdominal adiposity, WHtR in girls and WC in boys. However, small differences in discriminatory capabilities don't allow us to clearly defend the adoption of a single measure above all others.

Atrial fibrillation risk prediction from the 12-lead electrocardiogram using digital biomarkers and deep representation learning

Aims

This study aims to assess whether information derived from the raw 12-lead electrocardiogram (ECG) combined with clinical information is predictive of atrial fibrillation (AF) development.

Methods and results

We use a subset of the Telehealth Network of Minas Gerais (TNMG) database consisting of patients that had repeated 12-lead ECG measurements between 2010 and 2017 that is 1 130 404 recordings from 415 389 unique patients. Median and interquartile of age for the recordings were 58 (46-69) and 38% of the patients were males. Recordings were assigned to train-validation and test sets in an 80:20% split which was stratified by class, age and gender. A random forest classifier was trained to predict, for a given recording, the risk of AF development within 5 years. We use features obtained from different modalities, namely demographics, clinical information, engineered features, and features from deep representation learning. The best model performance on the test set was obtained for the model combining features from all modalities with an area under the receiver operating characteristic curve (AUROC) = 0.909 against the best single modality model which had an AUROC = 0.839.

Conclusion

Our study has important clinical implications for AF management. It is the first study integrating feature engineering, deep learning, and Electronic medical record system (EMR) metadata to create a risk prediction tool for the management of patients at risk of AF. The best model that includes features from all modalities demonstrates that human knowledge in electrophysiology combined with deep learning outperforms any single modality approach. The high performance obtained suggest that structural changes in the 12-lead ECG are associated with existing or impending AF.