[Differences between men and women in the prevalence of frailty and associated factors among older adults: evidence from ELSI-Brazil]

Based on a national representative sample of the population aged 50 years or older, this study aimed to estimate the prevalence of frailty among men and women, identify associated sociodemographic and health factors, and estimate the population attributable fraction. Data from the second wave (2019-2021) of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) were used. Frailty was classified based on the number of positive items among unintentional weight loss, exhaustion, low level of physical activity, slow gait, and weakness. The main analyses were based on multinomial logistic regression stratified by sex. The prevalence of frailty was lower in men (8.6%; 95%CI: 6.9; 10.7) than in women (11.9%; 95%CI: 9.6; 14.8), with the most frequent item being the low level of physical activity in both. Age and schooling level were the sociodemographic factors associated with pre-frailty and fragility among men and women. The population attributable fraction was different for frailty between genders. In men, the highest population attributable fraction was due to not having a partner (23.5%; 95%CI: 7.7; 39.2) and low schooling level (18.2%; 95%CI: 6.6; 29,7). In women, higher population attributable fraction values were due to memory deficit (17.1%; 95%CI: 7.6; 26.6), vision deficit (13.4%; 95%CI: 5.1; 21.7), and diabetes mellitus (11.4%; 95%CI: 4.6; 18,1). Similar population attributable fraction levels were observed for heart disease (8.9%; 95%CI: 3.8; 14.1 in women and 8.8%; 95%CI: 2.0; 15.6 in men). Strategies aimed at physical activity have the potential to prevent frailty in both men and women, and the prevention of chronic conditions is more important in women.

Who are the sexual and gender minorities who frequently interact with children and their association with healthcare

This study aimed to examine the sociodemographic profile of sexual and gender minorities who regularly interact with children and investigate whether such frequent interactions are associated with healthcare factors. This cross-sectional study utilized data from the LGBT+ Health Survey in Brazil, conducted online and anonymously from August to November 2020 with 958 participants. Regular interaction with children was defined as living with children or engaging in bi-weekly face-to-face meetings with children residing in different households. Healthcare factors encompass having a professional or reference service, feeling comfortable in discussing personal issues, and receiving worse quality medical or hospital care. The statistical analysis used the Poisson regression with robust variance. The prevalence of interaction with children was 5.3%. We observed a statistically higher prevalence among cisgender women (13.4%) and Black/brown and other non-white people (7.9%) after adjusting for age. The results showed a positive association only between regular interaction with children and worse-quality medical or hospital care received (PR=6.00; 95%CI 1.22-29.67). These findings highlight a persistent stigma and prejudice within healthcare services.

[Sociodemographic characteristics associated with underweight and overweight in adults aged 50 years and over (ELSI-Brasil): differences between sexes]

The objective were to describe the prevalence of underweight and overweight, assessed by body mass index (BMI), stratified by sex and age group, and to analyze the sociodemographic characteristics associated with BMI in older women and men. This is a cross-sectional analysis of 8,974 participants aged ≥ 50 years from the baseline of the Brazilian Longitudinal Study of Aging (ELSI-Brasil, 2015-2016). BMI was classified as underweight, eutrophy, and overweight according to the participant's age. A multinomial logistic regression model was used, considering the sociodemographic characteristics of women and men. The results showed a higher prevalence of overweight in women compared to men (64.1% vs. 57.3%). In both sexes, the prevalence of underweight was higher in the longest-lived individuals, while overweight was lower. In women, the chance of underweight was higher than the chance of eutrophy in those who were single/widowed/divorced (OR = 1.95; 95%CI: 1.42-2.66) and in those living in rural areas (OR = 1.58; 95%CI: 1.01-2.49), while the chance of being overweight was lower than the chance of being eutrophy in those living in rural areas (OR = 0.78; 95%CI: 0.62-0.97) and in all geographic macro-regions related to the South Region. For men, the chance of being overweight was lower than the chance of being eutrophy among single/widowed/divorced individuals (OR = 0.58; 95%CI: 0.48-0.69). The richest had a lower chance of being underweight (OR = 0.59; 95%CI: 0.38-0.90), as well as a higher chance of being overweight (OR = 1.52; 95%CI: 1.20-1.92). In conclusion, the sociodemographic characteristics associated with BMI differed between the sexes.

Differences in determinants of active aging between older Brazilian and English adults: ELSI-Brazil and ELSA

This study aimed to investigate differences in determinants of active aging between older Brazilian and English adults and to verify the association of behavioral, personal, and social determinants with physical health. This cross-sectional study was based on the ELSI-Brazil (2015-2016) and ELSA (2016-2017) cohorts. Active aging determinants included behavior (smoking, sedentary lifestyle, and poor sleep quality), personal (cognitive function and life satisfaction), and social determinants (education, loneliness, and volunteering), according to the World Health Organization. Physical health included activities limitation and multimorbidity. We estimated age- and sex-adjusted prevalence for each indicator and mean score, and used the negative binomial regression for statistical analysis. We included 16,642 participants, 9,409 from Brazil and 7,233 from England. Overall, all active aging determinants were worse in Brazil than in England, except for life satisfaction (no difference). The most remarkable difference was found for social determinants score in Brazil (mean difference of 0.18; p < 0.05), mainly due to a significantly lower education level in Brazil (70.6%; 95% confidence interval - 95%CI: 69.7-71.5) than England (37.1%; 95%CI: 35.1-39.1). All determinants (behavioral, personal, and social) were associated with health in Brazil and in England. However, the behavioral domain was stronger associated with health in England (coefficient = 2.76; 95%CI: 2.46-3.10) than in Brazil (coefficient = 1.38; 95%CI: 1.26-1.50; p < 0.001). Older English adults beneficiate more from healthier behaviors than Brazilians, which depend more on social policies.

Urban-rural differences in food consumption and environment and anthropometric parameters of older adults: results from ELSI-Brazil

This study aimed to identify dietary and anthropometric differences in older Brazilian adults (≥ 50 years old) living in urban-rural areas. This is a cross-sectional study with data from the second wave (9,949 participants) of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) from 2019-2021. Weekly dietary intake of fruit/vegetables, beans, and fish; self-perception of salt consumption; food environment (availability of fruit/vegetables in the neighborhood and self-production of food); and objective anthropometric parameters (body mass index [BMI] and waist circumference [WC]) were evaluated. Analyses were adjusted for schooling level. Compared to urban areas, rural areas show lower consumption of fruit/vegetables five days or more per week (74.6% vs. 86.4%) and greater adequate salt intake (96.8% vs. 92.1%) - differences we observed for men and women. Rural areas showed lower high WC (61.9% vs. 68%), significant only for men. Considering food environment, rural areas had lower fruit and vegetable availability in the neighborhood (41.2% vs. 88.3%) and higher self-production of food (38.2% vs. 13.2%). We observed a lower consumption of fruit/vegetables five days or more per week in rural areas with fruit/vegetable availability in the neighborhood and no self-production of food. Urban and rural areas show food and nutritional diversity. Incentives for fruit or vegetable consumption among residents in urban areas should consider the greater availability of these foods in their neighborhood, whereas, in rural areas, self-production of food should be encouraged. Adequate salt intake and ideal WC maintenance should be reinforced in urban areas.

Food consumption is associated with frailty in edentulous older adults: evidence from the ELSI-Brazil study

This cross-sectional study aimed to evaluate the association between food consumption (meat, fish, and fruits and vegetables), anthropometric indicators (body mass index, waist circumference, and waist-to-height ratio), and frailty; and to verify whether these associations vary with edentulism. We used data from 8,629 participants of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) (2015-16). Frailty was defined by unintentional weight loss, weakness, slow walking speed, exhaustion, and low physical activity. Statistical analyses included multinomial logistic regression. Of the participants, 9% were frail and 54% pre-frail. Non-regular meat consumption was positively associated with pre-frailty and frailty. Non-regular fish consumption, and underweight were associated only with frailty. Models with interactions reveled a marginal interaction between meat consumption and edentulism (p-value = 0.051). After stratification, non-regular meat consumption remained associated with frailty only in edentulous individuals (OR = 1.97; 95%CI 1.27-3.04). Our results highlight the importance of nutritional assessment, oral health, and public health-promoting policies to avoid, delay and/or reverse frailty in older adults.

Home-based gait speed and the association with sociodemographic and anthropometric variables: A national study (ELSI-Brazil)

OBJECTIVES

To investigate home-based gait speed performance for men and women stratified by age group and its associations with sociodemographic and anthropometric variables.

METHODS

Data from the 2^nd wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil, 2019-2021) were used. Gait speed was tested twice at home over 3.0 meters at usual pace. Associations of sociodemographic and anthropometric variables with gait speed were evaluated using gamma regression.

RESULTS

Median gait speed value reduced with increasing age in both sexes [men: 0.70 m/s (50-59 years) to 0.53 m/s (≥80 years); women: 0.68 m/s (50-59 years) to 0.48 m/s (≥80 years)] and was significantly lower in women than men in the age groups of 60-69 and 70-79 years. Age group and education among men and age group, education, and waist circumference among women were significantly associated with gait speed.

CONCLUSIONS

Our findings may be helpful as reference values to identify mobility limitation among older Brazilians.

The relationship between loneliness and healthy aging indicators in Brazil (ELSI-Brazil) and England (ELSA): sex differences

OBJECTIVES

This study aimed to estimate five harmonized healthy aging indicators covering functional ability and intrinsic capacity among older women and men from Brazil and England and evaluate their association with loneliness.

STUDY DESIGN

This was a cross-sectional study.

METHODS

We used two nationally representative samples of men and women aged ≥60 years from the Brazilian Longitudinal Study of Aging (ELSI-Brazil) wave 2 (2019-2021; n = 6929) and the English Longitudinal Study of Aging wave 9 (2018-2019; n = 5902). Healthy aging included five separate indicators (getting dressed, taking medication, managing money, cognitive function, and handgrip strength). Loneliness was measured by the 3-item University of California Loneliness Scale. Logistic regression models stratified by sex and country were performed.

RESULTS

Overall, age-adjusted healthy aging indicators were worse in Brazil compared with England for both men and women. Considering functional ability, loneliness was negatively associated with all indicators (ranging from odds ratio [OR] = 0.26, [95% confidence interval (CI) 0.13-0.52] in English men regarding the ability to take medication to OR = 0.49 [95% CI 0.27-0.89] in Brazilian women regarding the ability to manage money). Considering intrinsic capacity, loneliness was negatively associated with a higher cognitive function (OR = 0.72; 95% CI 0.55-0.95 in English women) and a higher handgrip strength (OR = 0.61; 95% CI 0.45-0.83 in Brazilian women). Lonely women demonstrated lower odds of a higher number of healthy aging indicators than men in both countries.

CONCLUSIONS

Country-specific social environments should be targeted by public policies to decrease loneliness and promote healthy aging later in life.

A decreased trajectory of loneliness among Brazilians aged 50 years and older during the COVID-19 pandemic: ELSI-Brazil

This study aimed to estimate prevalence of loneliness among older Brazilian adults over the first seven months of the COVID-19 pandemic and to identify the predictors of loneliness trajectories. Pre-pandemic data derived from face-to-face interviews of participants of the 2019-2020 Brazilian Longitudinal Study of Aging (ELSI-Brazil), which is a nationally representative study of community-dwelling individuals aged 50 years and over. Pandemic data were based on three rounds of telephone interviews among those participants, conducted from May to October 2020. Loneliness was measured by a single-item question, considering those who had at least two repeated measures. Explanatory variables included depression, living alone, leaving home in the last week, and virtual connectedness in the last month. Mixed-effects logistic regression was used to estimate odds ratios with their 95% confidence intervals (95%CI) and to investigate loneliness trajectories and their predictors. In total, 5,108 participants were included. The overall prevalence of loneliness in the pre-pandemic period was 33.1% (95%CI: 29.4-36.8), higher than the pandemic period (round 1: 23.6%, 95%CI: 20.6-26.9; round 2: 20.5%, 95%CI: 17.8-23.5; round 3: 20.6%, 95%CI: 17.1-24.6). A significant interaction (p ≤ 0.05) was evidenced only between depression and time; participants with depression showed a greater reduction in loneliness levels. Although loneliness levels in Brazil have decreased during the pandemic, this pattern is not present for all older adults. Individuals with depression had a more significant reduction, probably due to feeling closer to their social network members during the stay-at-home recommendations.

Nationwide handgrip strength values and factors associated with muscle weakness in older adults: findings from the Brazilian Longitudinal Study of Aging (ELSI-Brazil)

BACKGROUND

Handgrip strength (HGS) is a simple, quick, inexpensive, and highly reliable method for the assessment of muscle strength in clinical practice and epidemiological studies. This study aimed at describing the HGS values by age group and sex in Brazilians aged 50 years and over, determining age group- and sex-specific cutoff points for muscle weakness, and investigating sociodemographic and anthropometric variables associated with muscle weakness for each sex.

METHODS

Data from the second wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) were analyzed. HGS was measured in the dominant hand using a hydraulic hand dynamometer. Fractional polynomial regression models were fitted to estimate the percentiles (P5, P10, P20, P25, P50, P75, P90, and P95) of HGS by age group and sex. The P20 of the maximum HGS by age group and sex was used to define muscle weakness. Associations between sociodemographic (racial self-classification, place of residence, schooling, and monthly household income per capita in tertiles) and anthropometric variables (body mass index and waist circumference) and muscle weakness, by sex, were evaluated using logistic regression.

RESULTS

The analytical sample included 7905 participants (63.1 ± 9.1 years; 60% women). HGS reduced with increasing age in both sexes. Men presented higher HGS than women in all age groups. The cutoff points for muscle weakness ranged from 28 to 15 kg for men and from 17 to 9 kg for women. In the adjusted analyses, low schooling (0-4 years) was positively associated with muscle weakness in both sexes (in men, odds ratio (OR) 2.45, 95% confidence interval (CI) 1.46-4.12; in women, OR 1.90, 95%CI 1.18-3.06). Low and middle monthly household income per capita also had a positive association with muscle weakness among women (OR 1.78, 95%CI 1.37-2.32; OR 1.32, 95%CI 1.01-1.73, respectively). Overweight had a negative association with muscle weakness among men (OR 0.66, 95%CI 0.52-0.83), and obesity was inversely associated with muscle weakness in both sexes (in men, OR 0.49, 95%CI 0.31-0.78; in women, OR 0.69, 95%CI 0.52-0.92).

CONCLUSIONS

This study provides HGS values and cutoff points for muscle weakness by age group and sex from a nationally representative sample of older Brazilian adults. The variables associated with muscle weakness slightly differed between men and women. HGS values and cutoff points generated can be used as benchmarks in clinical settings and foster future epidemiological research.

Education and income-related inequalities in multimorbidity among older Brazilian adults

OBJECTIVES

This study aimed to evaluate the existence of socioeconomic inequalities related to the prevalence of multimorbidity in the Brazilian population aged 60 and older.

METHODS

This was a cross-sectional study with data from the last Brazilian National Health Survey (PNS) collected in 2019. Multimorbidity was the dependent variable and was defined as the presence of two or more chronic diseases. All the diseases were assessed based on a self-reported previous medical diagnosis. Education and per capita family income were the measures of socioeconomic position. Socioeconomic inequalities related to multimorbidity were assessed using two complex measures of inequality; the Slope Index of Inequality (SII) and the Concentration Index (CI).

RESULTS

The prevalence of multimorbidity in Brazil was 56.5% 95% CI (55.4; 57.6) and varied from 46.9% (44.3; 49.6) in the North region to 59.3% (57.0; 61.5) in the South region. In general, individuals with higher socioeconomic positions had a lower prevalence of multimorbidity. Significant absolute and relative income inequalities were observed in the South region [SII -9.0; CI -0.054], Southeast [SII -9.8; CI -0.06], and Middle-east [SII -10.4; CI -0.063]. Absolute and relative education inequalities were significant for the country and two of its regions (Southeast [SII -12.7; CI -0.079] and South [SII -19.0; CI -0.109]).

CONCLUSIONS

The prevalence of multimorbidity is high in Brazil and all of its macro-regions. The significant findings concerning the inequalities suggest that the distribution of this condition is more concentrated among those with lower education and income.

COVID-19 vulnerability among Brazilian sexual and gender minorities: a cross-sectional study

Minority groups are more prone to worsen their personal and social vulnerabilities during the COVID-19 pandemic. This study aimed to identify factors associated with the highest COVID-19 vulnerability in the Brazilian sexual and gender minorities. This is a cross-sectional study based on 826 respondents of the Brazilian LGBT+ Health Survey, conducted online from August to November 2020. The COVID-19 vulnerability was based on a previous vulnerability index created by an LGBT+ institution, which comprises three dimensions (income, COVID-19 exposure, and health). The outcome was the highest score quartile. Statistical analysis was based on logistic regression models. The COVID-19 vulnerability was higher in heterosexual and other scarce sexual orientations (OR = 2.34; 95%CI: 1.01-9.20, vs. homosexual), cisgender men (OR = 3.52; 95%CI: 1.35-4.44, vs. cisgender women), and those aged ≥ 50 years (OR = 3.74; 95%CI: 1.24-11.25, vs. 18-29 years old). A negative association was found with complete graduate education (OR = 0.06; 95%CI: 0.02-0.22, vs. complete high school), being white (OR = 0.44; 95%CI: 0.23-0.83), and proper facemask use (OR = 0.31; 95%CI: 0.13-0.76). Except for proper facemask use, factors associated with higher COVID-19 vulnerability are structural determinate and suggest overlapping vulnerabilities, as described by the syndemic model. It guides strategies to deal with the pandemic, which includes a joint approach to the common epidemic that affects sexual and gender minorities, broadening the intersectoral approach to decrease inequalities.

Loneliness and social disconnectedness in the time of pandemic period among Brazilians: evidence from the ELSI COVID-19 initiative

Objectives: This study aimed at estimating the pre-pandemic and pandemic prevalence of loneliness and investigating the association of loneliness with social disconnectedness during social distancing strategies in the time of the COVID-19 pandemic period.Methods: We used data from the ELSI COVID-19 initiative with participants from the Brazilian Longitudinal Study of Aging (ELSI-Brazil), which comprised 4,431 participants aged 50 years and over. Loneliness (hardly ever/some of the time/often) was assessed by the question "In the past 30 days, how often did you feel alone/lonely?". Social disconnectedness included information on social contacts through virtual talking (i.e. telephone, Skype, WhatsApp, or social media) and outside-home meetings with people living in another household. Covariates included sociodemographic and health related characteristics. Multinomial logistic regression models were used to estimate odds ratios (OR) with their 95% confidence interval (CI).Results: The overall prevalence of loneliness during the pandemic was 23.9% (95% CI 20.7-27.5); lower than in the pre-pandemic period (32.8%; 95% CI 28.6-37.4). In the pandemic period, 20.1% (95% CI 16.9-23.6) reported some of the time feeling lonely and 3.9% (95% CI 3.1-4.8) reported often feeling lonely. In the fully adjusted model, virtual talking disconnectedness (OR=1.67; 95% CI 1.09-2.56) was positively associated with some of the time feeling lonely and outside-home disconnectedness (OR=0.33; 95% CI 0.18-0.60) was negatively associated with often feeling lonely.Conclusion: Individuals with virtual talking disconnectedness and without outside-home disconnectedness are at higher risk of loneliness during the time of COVID-19 pandemic. Stimulating virtual talking connectedness might have the potential to diminish loneliness despite steep outside-home disconnectedness.

Association Between Physical Functioning and Time Until a New Hospitalization in Community-Dwelling Older Adults: A Prospective Cohort Study

BACKGROUND AND PURPOSE

Physical functioning refers to the ability to independently perform activities that require physical ability, and may be an important tool for predicting a higher risk of hospitalization. The objective of this study was to verify whether aspects of physical functioning are independently associated with the risk for new hospitalization in older adults seen in primary health care.

METHODS

This prospective cohort study consisted of 473 older adults 60 years and older who had not been hospitalized in the prior year. Hospitalization records were obtained with authorization from the hospital admission. Depending on physical functioning, the probability of a new hospital admission within the next 5 years was determined based on survival analysis and the Kaplan-Meier curve. Physical functioning was evaluated using 5 easy-to-administer tests: handgrip strength using a Jamar dynamometer, functional performance using the Short Physical Performance Battery, balance using the step test, mobility using the Timed Up and Go (TUG) test, and gait speed using the 4-m walk test. The association between poor physical functioning and new hospitalization was verified using a Cox regression model, adjusted for sex, age, number of comorbidities, number of medications, and BMI. Models were implemented separately for each physical functioning test.

RESULTS

In the sample, 32% had been hospitalized at least once in 5 years. The Kaplan-Meier curve showed a decrease in the probability of nonhospitalization within the next 5 years. Cox regression analysis showed an association between hospitalization within the next 5 years and mobility on the TUG test of more than 12.4 seconds in the crude (hazard ratio [HR] = 1.33, 95% CI = 1.10-1.60) and adjusted models (HR = 1.26, 95% CI = 1.02-1.56), and balance using the step test of more than 7.5 seconds in the crude (HR = 1.27, 95% CI = 1.03-1.56) model.

CONCLUSIONS

Physical functioning tests demonstrated that poor physical performance predicts new hospitalization, and reinforced the importance of their application in physical therapy practice in primary health care settings.

Fatores associados à piora no estilo de vida durante a pandemia de COVID-19 na população brasileira de lésbicas, gays, bissexuais, transexuais, travestis e identidades relacionadas: estudo transversal

Resumo OBJETIVO: Verificar fatores associados à piora do estilo de vida, incluindo atividade física e consumo de cigarros e álcool, durante a pandemia de COVID-19, entre lésbicas, gays, bissexuais, transexuais, travestis e identidades relacionadas, Brasil, 2020. MÉTODOS: Estudo transversal, com indivíduos ≥18 anos de idade. Odds ratio (OR) e intervalos de confiança de 95% (IC95%) foram estimados pela regressão logística. RESULTADOS: Dos 975 participantes, 48,9% (IC95% 45,7;52,1) diminuíram sua atividade física; 6,2% (IC95% 4,8;7,9) e 17,3% (IC95% 15,0;19,8) aumentaram o consumo de cigarros e de álcool, respectivamente. Houve piora na realização de atividade física nos que aderiram às máscaras (OR=2,26; IC95% 1,20;4,23), piora no consumo de cigarros naqueles com alguma condição crônica (OR=2,39; IC95% 1,03;5,56) e de álcool nas mulheres cis (OR=1,95; IC95% 1,31;2,92) e indivíduos morando com companheiro(a) (OR=1,89; IC95% 1,23;2,91) CONCLUSÃO: Destacou-se piora do estilo de vida em mulheres cis, indivíduos com uma condição crônica e aqueles que aderiram às máscaras.

Difficulty in taking medication and stroke among older adults with systemic arterial hypertension: the Fibra Study

This article aims to investigate whether difficulty in taking medication is associated with stroke among older adults with Systemic Arterial Hypertension (SAH) and to explore their association with living arrangements. Cross-sectional study was based on 3,502 older adults with SAH from the four universities pole of Frailty in Brazilian Older People (Fibra) Study, Brazil, including 14 municipalities of the five Brazilian regions. We used the medical diagnosis of stroke and difficulty in taking medications (self-reported difficulty and financial difficulty affording prescribed medications). Multivariate analysis was performed using logistic regression. Differently from women, older men with SAH, which report difficulty in taking medication (unintentional non-adherence), have higher odds of stroke. When stratified by living arrangements, those living with a partner have even higher odds of stroke compared to those without difficulty in taking medication and living alone. None association was found for difficulty affording prescribed medication for both men and women. Unintentional difficulty in taking medication plays a role in SAH treatment among men. Primary care strategies for controlling blood pressure should not be focus only on patients but targeting spouses as well.

The Brazilian LGBT+ Health Survey: methodology and descriptive results

The understanding of health care demands and possible access barriers may support policymaking and best practices targeting the lesbian, gay, bisexual, transgender, and related identities (LGBT+) population. The aims of the Brazilian LGBT+ Health Survey were to characterize the LGBT+ population during the COVID-19 pandemic and to specify the characteristics of the COVID-19 pandemic in this population. This is a cross-sectional online study, with a convenience sample of 976 individuals identified as LGBT+, aged 18 years or older from Brazil. It allows investigations of sexuality, discrimination, internal homophobia, health-related behaviors, and health care access. The study adopts a conceptual framework (i.e., validated tools and measures) common to other epidemiological studies, allowing comparisons. We describe the study methodology, some descriptive results, and health-selected indicators compared with the Brazilian National Health Survey. Most of the respondents were from Southeast Region (80.2%), mean aged 31.3 (± 11.5 years). Regarding COVID-19, 4.8% tested positive. Both weekly episodes of discrimination (36%) and depression prevalence (24.8%) were high among the LGBT+ population in Brazil, highlighting mental health and homophobia as major concerns in the LGBT+ context during the pandemic. Although a decade has passed since the institution of the Brazilian National Policy for Comprehensive LGBT Health, appropriate training of health professionals to offer adequate services is still needed. Knowledge of the specific health demands of this group might guide person-centered best practices, promote sexual minority high-acceptance settings, and contribute to higher equity during the pandemic.

[Predisposition to severe forms of COVID-19 and adherence to preventive measures: the role of social support]

This study sought to assess the adherence to preventive measures among the elderly more prone to severe forms of COVID-19, and the association and interaction with social support. It is a cross-sectional study conducted with a sample of 3,477 participants of the telephone survey of the Brazilian Longitudinal Study of Aging (ELSI-COVID-19 initiative), who reported going out of the home in the past week. The adherence was based on the frequency of leaving the house, the need to venture outside the home, use of masks, and sanitization of hands. Statistical analysis was based on the Poisson model with robust variance. Predisposing factors for severe forms of COVID-19 included age ≥65 years, hypertension, diabetes, and obesity. Social support included living arrangements and social distancing during the pandemic. Approximately 46% of the participants showed higher adherence, which was positively associated with the number of predisposing factors for severe forms of COVID-19. Social support was not associated with adherence, nor was this association modified after adjustments. The conclusion drawn is that higher adherence is concentrated among the elderly with greater predisposition to severe forms of COVID-19, irrespective of social support, albeit preventive measures should be adopted by all.

Relationship between work before the epidemic and having gone out to work during the epidemic among participants in the Brazilian Longitudinal Study of Aging: results of the ELSI-COVID-19 initiative

The objective of this study was to examine the prevalence of going out to work during the COVID-19 epidemic, and the factors associated with this, among adults aged 50 years and over who were in paid employment before its onset. We used data from the second wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil), conducted through face-to-face interviews between August 2019 and March 2020 (before the onset of the epidemic), in a representative national sample of adults aged 50 and over, and data obtained through telephone interviews carried out among the same participants (ELSI-COVID-19 initiative), conducted between May 26 and June 8, 2020 (during the epidemic). The analyses were based on odds ratios (OR) estimated by logistic regression. The participants' mean age was 59.9 years (SD = 6.5). The prevalence of going out to work in the previous seven days was 38.4% (95%CI: 31.3-46.1), 50.2% among men and 25.1% among women (formal work, self-employment, and informal work). The results showed that among men, the likelihood of going out to work was lower among those aged 60 to 69 years compared to those aged 50 to 59 years (OR = 0.27; 95%CI: 0.15-0.48). Among women, the likelihood was lower among those who were self-employed (OR = 0.28; 95%CI: 0.12-0.64) or in informal employment before the epidemic (OR = 0.25; 95%CI: 0.09-0.69), compared to those in formal employment. One of the hypotheses to explain this association is that women in informal employment were more likely to be dismissed, and that self-employed women have stopped working during the epidemic.

[Factors associated with preventive health services search among Brazilian adults: National Health Survey, 2013]

The objective of this article is to examine factors associated with preventive health services search among Brazilian adults. Sample included adults participants from the National Health Survey (2013), that had reported any health service search in prior 15 days, categorized into "treatment/diagnosis" or "preventive" service. Exploratory variables included sex, age, race, marital status, education, household situation, private health plan enrolment and time of FHS enrolment. Associations were verified by prevalence ratios (PR), estimated using robust Poisson regression, considering complexity of sampling parameters. Final sample included 32,377 individuals, 12,94% have searched "preventive" services. Preventive search was more often among women and less often among the older adults, those not living with partner, with less education. Having private health plan was associated with less preventive services search. FHS enrolment were not associated with preventive search. By conclusion, although some efforts and the importance of preventive actions, most of individuals search for treatment services.

[Ongoing employment and chronic conditions among community-dwelling elderly people: evidence from Rede Fibra in Belo Horizonte]

This cross-sectional study was based on a probabilistic sample of 597 community-dwelling elderly people living in Belo Horizonte. Theaim was to assess which chronic conditions are independently associated with ongoing employment among elderly people. It was conducted to assess the isolated effect of each one. The multivariate analysis was based on Poisson regression models with robust variance, adjusted by sex, age, schooling, retirement and chronic conditions. Arthritis (or rheumatism) was the only chronic condition with independent and statistic significant association with ongoing employment, even after adjustment for other chronic conditions: older people with medical diagnosis of arthritis have lower odds of being in the labor market (Fully adjusted Prevalence ratio [PR] = 0.54; CI 95%: 0.35-0.85). Moreover, our results showed that gender modifies this association, with a lower propensity among females (PR=0.45; CI 95%: 0.25-0.84). Our results highlight the importance of health promotion among workers, mostly arthritis prevention and management among women.

Inequalities in basic activities of daily living among older adults: ELSI-Brazil, 2015

OBJECTIVE

To evaluate the magnitude of wealth-related inequalities in basic activities of daily living among community-dwelling Brazilian older adults and to determine the contribution of demographic, socioeconomic, and health conditions to the inequality.

METHODS

We used data from the 2015 Brazilian Longitudinal Study of Aging (ELSI-Brazil) with a nationally representative sample of adults aged 50 years or older. We assessed wealth-related inequalities in basic activities of daily living by the concentration index. Concentration index was decomposed to determine the contribution of demographic, health, and socioeconomic factors to wealth-related inequalities in basic activities of daily living.

RESULTS

The prevalence of disability in the sample was 15.7% (95%CI 14.9–17.6). The concentration index was -0.145 (95%CI -0.194– -0.097), which indicates that disability is concentrated in the poorest individuals in Brazil. Inequalities in basic activities of daily living disability are primarily explained by socioeconomic status (wealth and own education) not by demographic or health factors.

CONCLUSIONS

There are avoidable wealth-related inequities for those with a disability in Brazil. The strong contribution of the socioeconomic status highlights the need for new public health policies that promote equity, universality, and integrality, in addition to the expansion of home nursing public services.

Depressive symptoms, emotional support and activities of daily living disability onset: 15-year follow-up of the Bambuí (Brazil) Cohort Study of Aging

Psychosocial factors appear to be associated with increased risk of disability in later life. However, there is a lack of evidence based on long-term longitudinal data from Western low-middle income countries. We investigated whether psychosocial factors at baseline predict new-onset disability in long term in a population-based cohort of older Brazilians adults. We used 15-year follow-up data from 1,014 participants aged 60 years and older of the Bambuí (Brazil) Cohort Study of Aging. Limitations on activities of daily living (ADL) were measured annually, comprising 9,252 measures. Psychosocial factors included depressive symptoms, social support and social network. Potential covariates included sociodemographic characteristics, lifestyle, cognitive function and a physical health score based on 10 self-reported and objectively measured medical conditions. Statistical analysis was based on competitive-risk framework, having death as the competing risk event. Baseline depressive symptoms and emotional support from the closest person were both associated with future ADL disability, independently of potential covariates wide range. The findings showed a clear graded association, in that the risk gradually increased from low emotional support alone (sub-hazard ratio - SHR = 1.11; 95%CI: 1.01; 1.45) to depressive symptoms alone (SHR = 1.52; 95%CI: 1.13; 2.01) and then to both factors combined (SHR = 1.61; 95%CI: 1.18; 2.18). Marital status and social network size were not associated with incident disability. In a population of older Brazilian adults, lower emotional support and depressive symptoms have independent predictive value for subsequent disability in very long term.

Pannexin channels increase propidium iodide permeability in frozen-thawed dog spermatozoa

Pannexins (Panx) are proteins that form functional single membrane channels, but they have not yet been described in dogs. The aim of the present study was to detect Panx1, Panx2 and Panx3 in frozen-thawed dog spermatozoa using flow cytometry and immunofluorescence analyses, evaluating the relationship of these proteins with propidium iodide (PI) in frozen-thawed spermatozoa. Fresh and frozen-thawed dog spermatozoa from eight dogs were preincubated with 3μM PI with or without 15μM carbenoxolone (CBX) or 1mM probenecid (PBD), two Panx channel inhibitors, and then incubated with rabbit anti-Panx1, anti-Panx2 and anti-Panx3 antibodies (1:200). Panx immunolocalisation was assessed by fluorescence microscopy. Flow cytometry data were evaluated by analysis of variance. All three Panx proteins were found in dog spermatozoa: Panx1 was mostly localised to the acrosomal and equatorial segment, Panx2 was found in the posterior region of the head and tail and Panx3 was localised to the equatorial and posterior head segment. The percentage of PI-positive cells determined by flow cytometry was reduced (P<0.05) in the presence of Panx inhibitors. These results show that Panx proteins are present in dog spermatozoa and increase PI permeability in frozen-thawed dog sperm, suggesting that the percentage of PI-positive spermatozoa used as an indicator of non-viable cells may lead to overestimation of non-viable cells.

Wealth and Disability in Later Life: The English Longitudinal Study of Ageing (ELSA)

We examined wealth inequalities in disability, taking into account the effect of both depression and social support among older English adults using data from 5,506 community-dwelling people aged 50 years and over from the English Longitudinal Study of Ageing (ELSA). Disability was measured as self-reported limitations in the Basic Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL). Depressive symptomatology was measured using the 8-item Center for Epidemiological Studies-Depression (CES-D) scale. Social support was assessed by marital status and frequency of contact with friends, relatives or children. Multinomial logistic regression models were used to assess the role of social support and depressive symptoms on disability by total household wealth, which is a measure of accumulated assets over the course of life. Our findings showed that the poorest men with disability were more likely to live without a partner and have no weekly contact with children, family or friends compared to the wealthiest. Among women with disability, the poorest were more likely to report loneliness and have no partner while the wealthiest and the intermediate groups were more likely to be living with a partner. There was a strong inverse dose-response association between wealth and depressive symptoms among all participants with disability. This study shows a clear wealth gradient in disability among older English adults, especially for those with elevated depressive symptoms.

Nutritional Risk is Associated with Chronic Musculoskeletal Pain in Community-dwelling Older Persons: The PAINEL Study

Malnutrition is a risk factor for noncommunicable diseases related to ageing, and it can also contribute to musculoskeletal health. This study investigated whether nutritional risk is associated with chronic musculoskeletal pain in community-dwelling older persons. Nutritional risk was assessed by the DETERMINE Checklist. Chronic musculoskeletal pain was defined as the presence of pain in the past six months that did not disappear for at least 30 consecutive days. Multivariate logistic regression including confounding variables was used for the analysis. The sample was comprised of 383 participants (age 75.6 ± SD 6.1); the majority were at moderate-to-high nutritional risk (69%) and approximately one third presented chronic musculoskeletal pain (30%). The nutritional risk score was independently associated with chronic musculoskeletal pain: adding one unit in the risk score produces an 11% increment in the odds of presenting pain (OR 1.109, 95% CI 1.022-1.204). Individuals classified into moderate- or high-risk categories also had substantially higher odds (∼90%) of presenting chronic musculoskeletal pain when compared to those in the low-risk category, although our findings were only marginally significant. This is the first study to demonstrate the association between nutritional risk and chronic musculoskeletal pain above and beyond the contributed effects from relevant confounders.

Functional performance and social relations among the elderly in Greater Metropolitan Belo Horizonte, Minas Gerais State, Brazil: a population-based epidemiological study

This study was conducted in a probabilistic sam- ple of 2,055 elderly in Greater Metropolitan Belo Horizonte, Minas Gerais State, Brazil, to examine components of social network (conjugal status and visits by the children, other relatives, and friends) and social support (satisfaction with personal relations and having persons on whom to rely) associated with limitations in performing basic activities of daily living (ADL). Multivariate analysis used the Hurdle model. Performance of ADL showed independent and statistically significant associations with social network (fewer meetings with friends and not having children) and personal support (dissatisfaction/indifference towards personal relations). These associations remained after adjusting for social and demographic characteristics, health status, and other indicators of social relations. Our results emphasize the need for greater attention to social network and social support for elderly with functional limitations and those with weak social networks and social support.

Grape epicatechin conjugates prevent erythrocyte membrane protein oxidation

Epicatechin conjugates obtained from grape have shown antioxidant activity in various systems. However, how these conjugates exert their antioxidant benefits has not been widely studied. We assessed the activity of epicatechin and epicatechin conjugates on the erythrocyte membrane in the presence and absence of a peroxyl radical initiator, to increase our understanding of their mechanisms. Thus, we studied cell membrane fluidity by fluorescence anisotropy measurements, morphology of erythrocytes by scanning electron microscopy, and finally, red cell membrane proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our data showed that incubation of red cells in the presence of epicatechin derivatives altered membrane fluidity and erythrocyte morphology but not the membrane protein pattern. The presence in the medium of the peroxyl radical initiator 2,2'-azobis(amidinopropane) dihydrochloride (AAPH) resulted in membrane disruptions at all levels analyzed, causing changes in membrane fluidity, cell morphology, and protein degradation. The presence of antioxidants avoided protein oxidation, indicating that the interaction of epicatechin conjugates with the lipid bilayer might reduce the accessibility of AAPH to membranes, which could explain in part the inhibitory ability of these compounds against hemolysis induced by peroxidative insult.

A polyphenol-enriched cocoa extract reduces free radicals produced by mycotoxins

Polyphenols are characterized by the presence of phenol units in the molecules. These compounds may show antioxidant ability by scavenging reactive oxygen species (ROS) of the free radical type. A polyphenol enriched cocoa extract (PECE) was obtained from cocoa seeds with 28% of procyanidins which were mainly epicatechin oligomers. PECE was very active as free radical scavenger against 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and tris(2,4,6-trichloro-3,5-dinitrophenyl)methyl (HNTTM) radicals; and the tris(2,3,5,6-tetrachloro-4-nitrophenyl)methyl (TNPTM) assay showed that the PECE might not be pro-oxidant. Thus it was considered a good candidate to be tested in in vitro models. It showed mild cytotoxic power on Hep G2 cells and induced ROS in a dose-dependent manner being weak oxidant only at high concentrations near the limit of solubility. The antioxidant properties were assayed in Hep G2 treated with the mycotoxins ochratoxin A (OTA) and/or aflatoxin B1 (AFB1). The PECE was not effective against AFB1 but it increased the cell viability and reduced significantly the amounts of ROS in cells treated with OTA or mixtures of AFB1+OTA. These results are coherent with the role of oxidative pathways in the mechanism of OTA and indicate that polyphenols extracted from cocoa may be good candidates as antioxidant agents.

Deleterious versus neuroprotective effect of metabolic inhibition after traumatic spinal cord injury

STUDY DESIGN

This work is an experimental and prospective study in adult, female, Long-Evans rats.

OBJECTIVES

The aim of this study was to probe the effect of metabolic inhibition after an acute traumatic spinal cord injury (TSCI) using a standardized contusion model (NYU impactor) to know whether the metabolic inhibition is a 'secondary mechanism of injury' or a mechanism of protection.

SETTING

All experimental procedures were carried out in the Mexico City.

METHODS

Animals were divided into five groups: one sham and four with TSCI, including no treatment, rotenone (inhibitor of mitochondrial complex I), sodium azide (inhibitor of mitochondrial complex IV) and pyrophosphate of thiamine or non-degradable cocarboxylase as a metabolic reactivator.

RESULTS

After TSCI, the metabolic inhibition with sodium azide treatment diminished the lipid peroxidation process (malondialdehyde levels by spectrophotometric procedures) and the damage to the spinal cord tissue (morphometric analysis), and increased the activity of creatine kinase and lactate dehydrogenase enzymes (P<0.05) (measured by spectrophotometric procedures 24 h after TSCI as well as after the functional recovery of the hind limb (evaluated weekly for 2 months by the BBB (Basso, Beattie and Bresnahan) scale)) when compared with the TSCI group without treatment.

CONCLUSION

The results show that the partial and transitory inhibition of the aerobic metabolism after an acute TSCI could be a self-protection mechanism instead of being a 'secondary mechanism of injury'.

The importance of polymerization and galloylation for the antiproliferative properties of procyanidin-rich natural extracts

Grape (Vitis vinifera) and pine (Pinus pinaster) bark extracts are widely used as nutritional supplements. Procyanidin-rich fractions from grape and pine bark extract showing different mean degrees of polymerization, percentage of galloylation (percentage of gallate esters) and reactive oxygen species-scavenging capacity were tested on HT29 human colon cancer cells. We observed that the most efficient fractions in inhibiting cell proliferation, arresting the cell cycle in G(2) phase and inducing apoptosis were the grape fractions with the highest percentage of galloylation and mean degree of polymerization. Additionally, the antiproliferative effects of grape fractions were consistent with their oxygen radical-scavenging capacity and their ability to trigger DNA condensation-fragmentation.

Functional fatty fish supplemented with grape procyanidins. Antioxidant and proapoptotic properties on colon cell lines

This work shows the properties of grape procyanidins with additional anticarcinogenic properties for increasing the shelf life of functional seafood preparations. Galloylated procyanidins (100 ppm, 2.7 mean degree of polymerization, 25% galloylation) extended the shelf life of minced horse mackerel muscle stored at 4 degrees C more than 8 days compared to controls without addition of polyphenols. The levels of endogenous alpha-tocopherol, EPA, and DHA of fish muscle were also preserved after 10 days at 4 degrees C. Therefore, the presence of procyanidins increased the stability of a product based on minced fish muscle during cold storage and maintained its functionality associated with the presence of polyunsaturated fatty acids and alpha-tocopherol. In addition, grape procyanidins showed a significant capacity to induce apoptosis in colon cancer cells (HT29 cell line) while being inactive in noncancer control cells (IEC-6). Thus, the product based on fatty fish muscle supplemented with grape procyanidins appears to be a stable functional food offering the combined action of omega-3 fatty acids and natural polyphenols.

Conjugation of catechins with cysteine generates antioxidant compounds with enhanced neuroprotective activity

Antioxidant compounds derived from the conjugation of (-)-epicatechin and (-)-epicatechin 3-O-gallate with cysteine and cysteine derivatives protected HT-22 nerve cells (EC50 between 36 and 65 microM) from death triggered by glutamate while underivatized (-)-epicatechin was almost inactive (EC50=610 microM). Differences in free radical scavenging capacity (DPPH assay) could not account for the improvement in neuroprotective activity upon derivatization of (-)-epicatechin with thiols. Moreover, while the gallate-containing compounds are more efficient radical scavengers than their non-galloylated counterparts, they are only equally or less potent as neuroprotective agents. Although all of the conjugates were able to scavenge mitochondrially generated reactive oxygen species (ROS) inside the cells, the majority of their neuroprotective activity appeared to be dependent upon their ability to maintain glutathione levels. These results suggest that a mechanism other than ROS scavenging is involved in the neuroprotective action exerted by the epicatechin conjugates.

[Permanent endovascular occlusion of the middle cerebral artery in Wistar rats: a description of surgical approach through the internal carotid artery]

INTRODUCTION

The importance of cerebral ischemia in clinical practice has driven the development of diverse experimental models of its different forms and different methods of producing it have been described. Here we report our experience with the use of the internal carotid artery (ICA) as an access route for the permanent endoluminal occlusion of the middle cerebral artery (MCA) in Wistar rats, and a detailed description of the procedure.

AIMS

Our aim at the at the Universidad de Cuenca Research Institute was to establish a standard technique for the constant and repeatable production of a focal cerebral infarct in the MCA territory in Wistar rats.

MATERIALS AND METHODS

Using a cervical approach, the ICA was dissected in 20 Wistar rats and, by means of an arteriotomy, a 25 mm long nylon 3-0 or 4-0 filament was introduced until the MCA was obstructed. The infracted area was delimited with 2,3,5-triphenyltetrazolium chloride and its volume was calculated using computer software.

RESULTS

Positive results were obtained in 10 cases, the mean volume of the infarct was 488.84 mm3, and the standard error was found to be 63.91 mm3. Subcortical infarcts occurred on three occasions. Two cases presented subarachnoid haemorrhage and two others showed parenchymatous haemorrhages; there were three deaths.

CONCLUSIONS

The use of the ICA as an entry point is an effective alternative for the endovascular production of focal cerebral ischemia and the use of a nylon 4-0 filament was more efficient than using a calibre 3-0 filament.

Percutaneous absorption of flavan-3-ol conjugates from plant procyanidins

Catechins (flavanols) are strong antioxidants, free radical scavengers and inhibitors of lipid peroxidation. New bio-based antioxidant compounds obtained by depolymerization of plant polymeric flavanols (procyanidins) in the presence of cysteine or cysteamine, as well as their underivatized counterpart, (-)-epicatechin, were evaluated in terms of their percutaneous absorption profiles taking into account their free radical scavenging efficiency. The evaluation of the percutaneous absorption of flavanols was carried out by an in vitro methodology using both pig and human skin. A good correlation was obtained using both skins in the evaluation of the skin absorption profiles. It can be deduced that 4beta-(S-cysteinyl)epicatechin (Cys-Ec) has a tendency to be located mainly in the outermost layers of the skin, whereas 4beta-(2-aminoethylthio)epicatechin (Cya-Ec) has a pronounced percutaneous absorption capacity. Their antioxidant properties and their skin penetration profiles support their potential cosmetic or pharmacological applications.

Mutual information and the homeopathic effect

We explore the feasibility of using mutual information to characterize the homeopathic effect. This quantity measures the information gained about a signal at time (t + tau), from its value at an earlier time t; it quantifies the predictability of data. We illustrate our method with an analysis of the homeopathic effect of Strophanthus hispidus on the cardiac rhythm of healthy human subjects, using data from a previous experiment. Our results allow an intuitively clear rendering and agree with the similitude principle applied to this case. They also show that the solvent has a significant effect on the signal; hence, it does not act as an ideal placebo and we discuss some therapeutic corollaries to this observation.

Cation-exchange micropreparative separation of galloylated and non-galloylated sulphur conjugated catechins

Catechin conjugates bearing an amino function can be separated from underivatized monomers by cation-exchange chromatography. Here, chromatographic conditions for the separation of epicatechin gallate-containing conjugates from the non-galloylated conjugates at micropreparative scale are described. The separation was achieved by exploiting either the hydrophobic or hydrophilic interactions of the conjugates with the core polymer. The retention was modulated by changing the amount of organic co-solvents (MeOH, EtOH, CH3CH, THF) in the elution buffers. The best resolution compatible with small peak widths was obtained at 20-30% EtOH. The experiments were reproducible.

On the physical basis of succussion

It is argued that succussion drives the homeopathic tincture undergoing potentisation to a turbulent regime, where vortices continually form and disappear, ranging in size from the linear extent of the container to a minimum scale determined by viscosity and the rate of energy dissipation. Input mechanical energy cascades down this population of eddies and becomes available at the microscopic level to perform work (chemical, electrical, etc). A structure generated in the tincture would be rupted by vortices smaller than it, and this sets definite limits on the strength of succussion, so the power input leads to larger vortices than the structures one is trying to create and preserve through potentisation. An experimental procedure to test this proposal is suggested, based on Rayleigh scattering.

Cysteinyl-flavan-3-ol conjugates from grape procyanidins. Antioxidant and antiproliferative properties

New bio-based antioxidant compounds have been obtained by depolymerisation of grape polymeric flavanols in the presence of cysteine. Their preparation and purification, as well as their antiradical/antioxidant and antiproliferative properties are reported. 4beta-(S-cysteinyl)epicatechin 5, 4beta-(S-cysteinyl)catechin 6 and 4beta-(S-cysteinyl)epicatechin 3-O-gallate 7 were efficiently purified from the crude depolymerised mixture by cation-exchange chromatography and preparative reversed-phase chromatography. The new compounds were more efficient than the underivatised (-)-epicatechin 1 as scavengers of the 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH) and weak growth inhibitors of human colon carcinoma HT29 cells. The order of antiradical and antiproliferative efficiency was 7 >5 approximately 6 >1, the same for both assays.

Homeopathic effect: a network perspective

There are two aspects to the problem of describing the homeopathic effect in physical terms: the nature of the therapeutic agent, and the system on which it acts. The latter can be considered as a network, which provides a conceptual framework that throws new light on long-standing questions, based on generic results such as the enhanced susceptibility of networks near critical states. It suggests a characterisation of health and disease in terms of distance from a critical state. The Internet provides a concrete analogy. This predicts a limiting condition on the acceptable loss of highly connected nodes in the system, and suggests a procedure to measure its connectivity and related parameters.

New flavanol derivatives from grape (Vitis vinifera) byproducts. Antioxidant aminoethylthio-flavan-3-ol conjugates from a polymeric waste fraction used as a source of flavanols

A new family of antioxidants has been obtained from a residual fraction of polymeric polyphenols of grape origin. The integral exploitation of resources is important in any sustainable production scheme. Many byproducts and residues generated by the agroindustries contain polyphenols with potential application as preventative agents against cancer and cardiovascular diseases. Among these polyphenols oligomeric proanthocyanidins are particularly significant. The polymeric forms, considered of less interest because of their astringent properties, constitute the largest portion of the biologically active plant proanthocyanidins. The new compounds described here result from the breakdown of polymeric flavanols in the presence of cysteamine and bear an amino function, which facilitates their isolation from complex mixtures by cation-exchange gels or resins. In this way, valuable antioxidant molecules can be efficiently obtained from otherwise wasted polymers. The new molecules appear to be as effective as their underivatized counterparts (flavan-3-ols) as antioxidants.

Respiratory sinus arrhythmia from two coupled pacemakers

We reproduce global features of respiratory sinus arrhythmia (RSA), a prominent source of heart rate variability, from two signals coupled in alternate fashion so dominance periodically switches back and forth between them. We consider two different possibilities for this coupling and illustrate our method with numerical simulations that we contrast with the corresponding results from real data. We interpret our findings within the context of the two-pacemaker model of the heartbeat, an alternative to the single-pacemaker mechanism of pulse generation in the orthodox conduction model.

Biological power laws and Darwin's principle

Assuming that the repertoire of responses by living systems to perturbation gives a measure of their Darwinian fitness in a rapidly fluctuating environment, those that fulfill allometries (power laws) are described by means of catastrophes, whose variables and parameters are smooth functions of biological attributes. Using empirical allometries from a given system as input, a method is proposed to construct its associated catastrophe, allowing specific predictions on its susceptibility to perturbation and related properties, based on general results from catastrophe theory. The method is discussed within the macroecological context, and an example is provided by applying it to ecological systems that satisfy the self-thinning rule.

Homeopathic effect on heart rate variability

We record ECGs from healthy human subjects during 24-h long intervals, using ambulatory equipment. We calculate from the data various parameters, searching for those that change in a clear and systematic way under a homeopathic stimulus, (Strophantus hispidus 30c). The energy fraction at high frequencies in the power spectrum of heart rate variability fulfills this condition, and we are able to interpret our results in a way consistent with the information on this medicine in the homeopathic Materia Medica.

Immunohistochemical evidence of the presence of aromatase P450 in the rat hypophysis

In order to analyze whether aromatase is present in the hypophysis of adult rats, we have performed an immunohistochemical study in young adult male and female rats. Our study has revealed that the hypophysis of adult rats contains aromatase, although marked differences are found between the sexes. The hypophyses of male rats have cells immunoreactive for the enzyme, 34.40% of these hypophyseal cells showing reaction. By contrast, cells from female rats show very little reaction, only 0.84% of them being reactive. No significant differences in the percentage of immunoreactive cells between one phase and another are observed during the estrous cycle. Our results point to the immunohistochemical expression of aromatase in the hypophysis of adult rats and at the same time suggest that its expression is sex-dependent. The enzyme may therefore be involved in the regulation of adenohypophyseal cytology by androgens.

Selective and conventional house-spraying of DDT and bendiocarb against Anopheles pseudopunctipennis in southern Mexico

Indoor feeding behaviors and mortalities of Anopheles pseudopunctipennis females were evaluated following contact with selective (bands covering mosquitoes' preferred resting areas) and full applications of DDT and bendiocarb on indoor sprayable surfaces. The DDT residues provoked strong avoidance behavior. To a lesser degree, mosquitoes were also repelled by bendiocarb-sprayed surfaces. Because of strong irritancy/repellency, unfed mosquitoes were driven outdoors in proportionally higher numbers. The resting time on selectively or fully DDT-sprayed huts was greatly reduced in comparison to bendiocarb-sprayed huts. Although unfed mosquitoes tended to rest on non-DDT-sprayed surfaces in the selectively treated hut, the man-biting rate was similar with both types of treatments. Unfed mosquitoes were repelled less from selectively bendiocarb-treated surfaces. Similar reductions in postfed resting times were observed on all surfaces suggesting that once fed, mosquitoes rested on sprayed surfaces for shorter intervals of time. Engorged mosquitoes had normal resting behavior (pre- and postspray) within the range of preferred resting heights in both DDT- and bendiocarb-sprayed huts, but the proportion of mosquitoes fed in the DDT-treated huts was lower. Selective spraying of walls was as effective as spraying the complete walls with both insecticides, but DDT was more effective in reducing mosquito-human contact. These studies show that by more effectively targeting vector behavior, a cost-effective alternative to traditional control techniques can be achieved.

Reaction medium engineering in enzymatic peptide fragment condensation: synthesis of eledoisin and LH-RH

The influence of different reaction systems on alpha-chymotrypsin-catalyzed synthesis of eledoisin and LH-RH peptides from (7 + 4) and (5 + 5) fragments was investigated. The peptide yield was determined in the following systems: buffered aqueous media, frozen solutions, organic media, and cosolvent mixtures. The experimental set up was tailored to allow the screening of an array of conditions with minimum consumption of peptide fragments (2.1 and 2.5 mM). The best yields (22% yield for eledoisin and 68% yield for LH-RH) were obtained in buffered aqueous solutions. It was found that the choice of buffer had a strong influence on the peptide yield; boric-borate and ammonium acetate buffers at pH 9, gave the best results. In buffered aqueous systems, both syntheses were scaled up by using a 10-fold increase in fragment concentration (21 and 25 mM). Under these conditions the yields rose to 57% and 80% of eledoisin and LH-RH, respectively. Moreover, during the synthesis of eledoisin and in the presence of boric-borate buffer pH 9, the peptide precipitated from the reaction medium preventing a secondary hydrolysis and facilitating the in situ product purification.

Resistance management strategies in malaria vector mosquito control. Baseline data for a large-scale field trial against Anopheles albimanus in Mexico

A high level of DDT resistance and low levels of resistance to organophosphorus, carbamate and pyrethroid insecticides were detected by discriminating dose assays in field populations of Anopheles albimanus in Chiapas, southern Mexico, prior to a large-scale resistance management project described by Hemingway et al. (1997). Biochemical assays showed that the DDT resistance was caused by elevated levels of glutathione S-transferase (GST) activity leading to increased rates of metabolism of DDT to DDE. The numbers of individuals with elevated GST and DDT resistance were well correlated, suggesting that this is the only major DDT resistance mechanism in this population. The carbamate resistance in this population is conferred by an altered acetylcholinesterase (AChE)-based resistance mechanism. The level of resistance observed in the bioassays correlates with the frequency of individuals homozygous for the altered AChE allele. This suggests that the level of resistance conferred by this mechanism in its heterozygous state is below the level of detection by the WHO carbamate discriminating dosage bioassay. The low levels of organophosphate (OP) and pyrethroid resistance could be conferred by either the elevated esterase or monooxygenase enzymes. The esterases were elevated only with the substrate pNPA, and are unlikely to be causing broad spectrum OP resistance. The altered AChE mechanism may also be contributing to the OP but not the pyrethroid resistance. Significant differences in resistance gene frequencies were obtained from the F1 mosquitoes resulting from adults obtained by different collection methods. This may be caused by different insecticide selection pressures on the insects immediately prior to collection, or may be an indication that the indoor- and outdoor-resting A. albimanus collections are not from a randomly mating single population. The underlying genetic variability of the populations is currently being investigated by molecular methods.