[Secular trends in respiratory diseases of childhood in the city of São Paulo, Brazil (1984-1996)]

OBJECTIVE

Data from two consecutive household surveys undertaken in mid-80s and mid-90s allow to characterize and analyse secular trends in infant and child respiratory diseases in the city of S. Paulo, Brazil.

METHODS

The two surveys included random population samples aged from zero to 59 months (1,016 in the period of 1984-85 and 1,280 in 1995-96). In both surveys the instant prevalence of high respiratory diseases (above the epiglottis) and low respiratory diseases with or without wheezing were calculated. All sampled children were examined in their household at a random day by trained pediatricians using standardized procedures. The examinations included medical history, past respiratory diseases and a complete physical examination. In both surveys the examinations were distributed throughout a period of almost 12 months to assure a uniform coverage of the various areas of the city along the four seasons of the year. For each survey, the study of the social distribution of the diseases took into account tertiles of the per capita family income. For the study of the determinants of secular trends, hierarchical causal models, multivariate regression analyses and calculations analogous to the ones used to assess population attributable risks were applied.

RESULTS/CONCLUSIONS

In the time span from the first to the second survey, there was a substantial increase in the prevalence of both low (from 22.2% to 38.8%) and high respiratory diseases (from 6.0% to 10.0% and from 0.8% to 2.8%, without and with wheezing, respectively). In the case of high respiratory disease and low respiratory disease without wheezing, an increase in prevalence was observed among all social strata, which did not interfere with the slightly less favourable situation of the lower income groups. In the case of low respiratory disease with wheezing, the increase was only observed among middle and low-income groups, being particularly high among the lower income group, yielding a significant inverse gradient between income and respiratory disease. Positive changes in distal (family income and maternal schooling) and in intermediate determinants related to housing characteristics would have resulted in a decline, not an increase, in the prevalence of respiratory diseases in the city. The duplication in the attendance rate to day care nurseries seen in the period could have counterbalanced the positive effect due to socioeconomic and housing variables but would not be enough to explain an increase in the disease.

[Secular trends in postanal growth in the city of São Paulo, Brazil (1974-1996)]

OBJECTIVE

Data from three household surveys undertaken in the city of S. Paulo, Brazil, from mid-80s to mid-90s allow to characterize and analyse secular trends in infant and child linear growth.

METHODS

In the three surveys, random population samples aged from zero to 59 months (1,008 children in the period of 1974-75; 1,016 in 1984-85 and 1,280 in 1995-96) were studied. Recumbent length was obtained from children up to 24 months of age and then stature was recorded. The international growth standard was used to evaluate the child's height according to age and sex. For the study of the social distribution of growth status, tertiles of the per capita family income was taken into account in each survey. For the study of the determinants of secular trends, hierarchical causal models, multivariate regression analyses and calculations analogous to the ones used to assess population attributable risks were applied.

RESULTS/CONCLUSIONS

In the period of 22 years covered by the three surveys, the secular trend of child growth in S. Paulo City showed a positive, continuous and apparently uniform curve. It was equivalent to a total average gain of 0.650 z scores of the international growth reference, or near 2.3 cm at the age of 30 months. The higher gain was observed among the third poorest fraction of the population--3.3 cm--and the lower gain--1.7 cm--among the third richest. Positive changes in distal determinants (family income and maternal schooling) and intermediate determinants (housing, sanitation, access to health services and reproductive past history) of child growth explained substantially part of the improvements seen from the mid-80s to mid-90s.

[Evolution of socioeconomic determinants of health in childhood in the city of São Paulo, Brazil (1984-1996)]

OBJECTIVE

Two consecutive household surveys undertaken in the mid-80s and mid-90s in the city of S. Paulo, Brazil, made possible to establish time trends of several child health determinants and indicators as well as to analyse the relationships among them. The study intends to report trends in socioeconomic determinants of child health.

METHODS

Random samples of the population aged from zero to 59 months were studied: 1,016 children in the period 1984-85 and 1,280 children in 1995-96. Both surveys investigated the family's per capita income and the mother's years of schooling. Nominal incomes were deflated according to the National Consumer Prices Index and expressed as values of October 1997.

RESULTS

From mid-80s to mid-90s average family income doubled and the proportion of low income families was reduced by 50% while average maternal schooling increased by 1.5 years and maternal illiteracy was almost eradicated. Income concentration increased in the period.

CONCLUSIONS

Increases in income and schooling are higher than those reported for the whole population in the country, which may be attributed to selective declines in fertility among the city's poorest families. The influence that changes in family income and maternal schooling may have exerted on several child health indicators is examined in subsequent articles.

[Evolution of environmental determinants of health in childhood in the city of São Paulo, Brazil]

OBJECTIVE

Two consecutive household surveys undertaken in mid-80s and mid-90s in the city of S. Paulo Brazil, made possible to establish time trends of several child health determinants and indicators as well as to analyse the relationships among them. The study intends to report trends in environmental determinants of child health.

METHODS

Random samples of the population aged from zero to 59 months were studied: 1,016 children in the period of 1984-85 and 1,280 children in 1995-96. Both surveys investigated several housing characteristics--materials used in the building, size, occupation density, existence of shower, toilet, running water in the kitchen, and the presence of smoker dwellers--as well as access to water supply, sewage, garbage disposal and pavement of public areas.

RESULTS

Improvements from mid-80s to mid-90s are observed regarding both housing characteristics and the implementation of basic services public services. The only indicator showing no improvement was the proportion of children living in slums, near 12% in both surveys. However, housing characteristics in slums showed an impressive improvement in the period between the surveys as well as the access of this population to water supply and garbage disposal services.

CONCLUSIONS

Improvements in housing characteristics are consistent with increases in the purchasing power reported in the same period. The expansion of public basic services resulted from both public investments and a significant reduction in population growth. The noticeable increase in the coverage of water supply and garbage disposal in the slums indicates a more equitable delivery of the basic services. The same trend was not seen regarding sewage and street paving, which are not widespread in slum areas. The influence that changes in the physical environment may have exerted on several child health indicators is examined in subsequent articles.

[Secular trends in intestinal parasitic diseases of childhood in the city of São Paulo, Brazil (1984-1996)]

OBJECTIVE

Data from two consecutive household surveys undertaken in mid-80s and mid-90s allow to characterize and analyse secular trends in infant and child intestinal parasitic diseases in the city of S. Paulo, Brazil.

METHODS

The two surveys included random population samples aged from zero to 59 months (1,016 in the period of 1984-85 and 1,280 in 1995-96). Stool samples were collected in both surveys and examined by sedimentation techniques using both unstained and Lugol-stained preparations. For each survey, the study of the social distribution of the parasitic diseases took into account tertiles of the per capita family income. For the study of the determinants of secular trends, hierarchical causal models, multivariate regression analyses and calculations analogous to the ones used to assess population attributable risks were applied.

RESULTS/CONCLUSIONS

In the time span from the first to the second survey, there was a substantial reduction in the prevalence of all parasites (from 30.9% to 10.7%), helminths in general (from 22.3% to 4.8%), giardiasis (from 14.5% to 5.5%) and two or more species of parasites (from 13.1% to 0.5%). A significant decline in prevalence was observed in all social strata and the inverse association between income and intestinal parasites was kept unchanged in the period. Positive changes in distal (family income and maternal schooling) and intermediate determinants (housing, sanitation, and access to health care) of helminthic disease could substantially explain part of its decline in the period. The decline in giardiasis was attributed to improvement in maternal schooling, housing and sanitation. The duplication in the attendance rate to day care nurseries may have restricted the decline rate in the giardiasis prevalence in the study period.

[Secular trends of height in adulthood of children born in the city of São Paulo, Brazil from 1950-1976]

OBJECTIVE

The purpose of this study was to estimate the secular trend/change in the height of young males born in the city of S. Paulo between 1950 and 1976 and measured in the year they turn 18 years.

METHODS

A random and representative sample (6,942 individuals) was evaluated in military draft. Statistical analyses included Shapiro-Wilk test for normality of height distribution in each birth cohort, and linear regression analysis for trend on heights.

RESULTS/CONCLUSIONS

Stature has increased 3.42 centimeters during the 27 years covered by the study (1.26 cm/decade). The trend was not linear: in the 50s, there was a statistically significant increase (0.84 cm/decade); in the 60s, a smaller but non-significant increase (0.5 cm/decade) was seen; in the period of 1970-76, a greater increase in heights (2.9 cm/decade) was observed. The secular change rate observed was comparable to the rate seen in other countries. The most recent birth cohorts (1975 and 1976) achieved the higher statures in the study (approximately 175 cm). Despite these height increments, deficits of 1.8 e 6.2 cm were seen when the taller cohorts of the study were compared to American young males born in 1961 (NCHS) and Dutch men born in 1972. If there won't be any changes in the accelerated rates of the 70s, young people of São Paulo may overcome these deficits in about one or three decades.

[Secular trends in birth weight in the city of São Paulo, Brazil (1976-1998)]

OBJECTIVE

Data from two household surveys on infant and child health status undertaken in the mid-80s and mid-90s, complemented with previous data collected from maternity hospitals records and more recent data provided by the state system on birth registries, allowed to characterize and analyse secular trends in birth weight in the city of S. Paulo, Brazil.

METHODS

The household surveys included random samples of children under 5 years old (n = 1,016 children in 1984-85 and n = 1,280 children in 1995-96). A random sample of births that took place in the city's hospitals in the year of 1976 (n = 5,734) was drawn from the hospital records. Birth registries refer to children born in the city between 1993 and 1998 (around 200,000 per year). The study of the social distribution of birth weight took into account the per capita family income and maternal schooling. For the analysis of the determinants of secular trends, hierarchical causal models, multivariate regression analyses and calculations analogous to the ones used to assess population attributable risks were applied.

RESULTS/CONCLUSIONS

Birth weight distribution in S. Paulo city (an average of 3,160 g and 8.9% of the values < 2,500 g) is below the expected for optimum fetal growth conditions (average 3,400-3,500 g and 4-5% of the values < 2,500 g). The birth weight distribution did not change substantially along the study period (1976-1998). However, there are evidences of changes when different socioeconomic strata are considered separately. Among the lower strata trends have been positive and this seems to be due to increases in intrauterine growth as a result of an improvement in family's purchasing power, women's weight and height, prenatal care and, possibly, the reduction in smoking. Among the higher socioeconomic strata, birth weight trends have been negative apparently due to an increase in premature births of unknown origin.

[Secular trends in malnutrition and obesity among children in the city of São Paulo, Brazil (1974-1996)]

OBJECTIVE

Data from three household surveys undertaken in the city of S. Paulo, Brazil, from mid-80s to mid-90s allow to characterize and analyse secular trends in malnutrition and obesity among infants and children.

METHODS

The three surveys included random population samples aged from zero to 59 months (1,008 children in the period of 1974-75; 1,016 in 1984-85 and 1,280 in 1995-96). The malnourished status was diagnosed when height-for-age and/or weight-for-height indices were below two standard deviation of the mean values expected according to the international growth reference. The obesity status was determined when weight-for-height indices fell two standard deviations above the reference. The study of the social distribution of malnutrition and obesity in each survey took into account tertiles of the per capita family income. For the study of the determinants of secular trends, hierarchical causal models, multivariate regression analyses and calculations analogous to the ones used to assess population attributable risks were applied.

RESULTS/CONCLUSIONS

In the period of 22 years covered by the three surveys, child malnutrition was controlled in the city and became relatively rare even among the poorest families. The risk of obesity remained low and restricted to the richest families. Positive changes in distal (family income and maternal schooling) and intermediate determinants (sanitation, access to heath services and reproductive past history) of child nutritional status substantially explained part of the decline in the prevalence of malnutrition seen in the mid-80s to mid-90s.

[Evolution of maternal and child health care in São Paulo (1984-1996)]

OBJECTIVE

Two consecutive household surveys undertaken in mid-80s and mid-90s in the city of S. Paulo, Brazil, made possible to establish time trends of several child health determinants and indicators as well as to analyse the relationships among them. The study intends to report trends in maternal and child health care.

METHODS

Random samples of the population aged from zero to 59 months were studied: 1,016 children in the period of 1984-85 and 1,280 children in 1995-96. Both surveys investigated three components of maternal and child health care: prenatal care, delivery and newborn care and routine health care provided to children up to five years of age (including development follow-up and vaccination).

RESULTS

Favourable changes seen in the period between the two surveys were the continuing universal birth coverage, significant increase in rooming-in in maternity hospitals and the number of routine visits for babies in their first year of life and, particularly, the universal outreach of the DPT, measles and tuberculosis vaccinations. Unfavourable trends were seen regarding the slight and clearly insufficient growth of prenatal care, the still high percentage (of near 50%) of cesarean sections, and the limited routine visits for children after their first year of age.

CONCLUSIONS

Estimates in the same period for the outreach of maternal and child health care in other urban areas of Brazil reinforce the unsatisfactory trends of the prenatal care in S. Paulo. Favourable comparisons are only seen regarding the outreach of child vaccination. The influence that changes in the maternal and child health care provided in the city may have exerted on several child health indicators is examined in subsequent articles.

[Secular trends in childhood in the city of São Paulo, Brazil (1984-1996)]

OBJECTIVE

Data from two consecutive households surveys undertaken in mid-80s and mid-90s allow to characterize and analyse secular trends in infant and child anaemia in the city of S. Paulo, Brazil.

METHODS

The two surveys included random population samples aged from zero to 59 months (1,016 in the period of 1984-85 and 1,280 in 1995-96). Capillary blood samples, collected by digital puncture in the two surveys, were analysed regarding their haemoglobin concentration. The anaemic status was determined when haemoglobin concentration was below 11 g/dL. For each survey, the study of the social distribution of child anaemia took into account tertiles of the per capita family income. For the study of the determinants of secular trends, hierarchical causal models, multivariate regression analyses and calculations analogous to the ones used to assess population attributable risks were applied.

RESULTS/CONCLUSIONS

In the time span from the first to the second survey, there was a significant reduction in the average haemoglobin concentration (from 11.6 g/dl to 11.0 g/dl), as well as a considerable increase in anaemia prevalence (from 35.6% to 46.9%). Unfavourable trends were observed in both sexes, all age groups and all income strata. Trends were still less favourable among the poorest families, aggravating the social burden related to child anaemia. Changes in distal (family income and maternal schooling) and proximal determinants (breast or bottle-feeding) of child anaemia were positive in the study period and therefore they cannot explain the increase in the disease. A low iron diet could explain the high prevalence of anaemia in both surveys but could not explain its further increase.

[Breastfeeding in two Brazilian State capitals: a comparative analysis]

This paper describes rapid assessment of infant feeding practices based on surveys conducted on National Immunization Day in the cities of Florianópolis and João Pessoa, Brazil. Two different infant feeding patterns emerge clearly in the data analysis. Most infants begin breastfeeding, but exclusive breastfeeding (EBF) from 0-4 months (46.3% in Florianópolis and 23.9% in João Pessoa) and timely complementary feeding rates (32.2% in Florianópolis and 24.8% in João Pessoa) are below recommended standards. EBF and breastfeeding duration medians were 53 and 238 days, respectively, in Florianópolis and 16.5 and 195 days, respectively, in João Pessoa. The results pointed to increasing breastfeeding rates and duration medians in Florianópolis as compared to João Pessoa. Use of these data could improve planning and monitoring of breastfeeding activities and infant nutrition policies.

[Changes in composition and appropriate nutrition of family diet in the metropolitan areas of Brazil (1988-1996)]

OBJECTIVE

A new family budget survey carried out in the mid-nineties in Brazil allows an update of the secular trends (1962-1988) of dietary patterns of Brazilian population living in metropolitan areas.

METHODS

Data sources are IBGE Institute of Statistics family budget surveys carried out from March 1987 to February 1988 (13,611 households) and from October 1995 to September 1996 (16,014 households) in all metropolitan areas of Brazil. The daily food availability per capita for each household was calculated dividing the total food acquired in a month by the number of individuals living in a household and the month's number of days. Dietary patterns were characterized according to the amount of selected food groups and nutrients relative to the diet caloric input. Comparisons between the two surveys included the metropolitan area population as a whole and subgroups from less (North and Northeast) and more developed (Mid-west, Southeast and South) regions.

RESULTS

It was observed an increase in consumption of meat and dairy products (except for butter) and a reduction in eggs consumption in both less and more developed regions. Beans, roots and tubers consumption showed a steady decline in the whole country while cereals consumption remained the same (higher in developed regions) or had a slight increase (in less developed regions). The proportional consumption of vegetal oils and margarine remained constant in the less developed regions but their consumption was greatly reduced in the more developed ones.

CONCLUSIONS

An increase in the diet's lipid content in less developed regions and of saturated fat in the country as a whole, associated with a decrease or even no consumption of beans, vegetables, fruits and complex carbohydrates, and a further increase in the excessive sugar consumption are the negative aspects of the trend observed from 1988 to 1996. Changes that may indicate a growing awareness of the population toward a healthier diet, such as a decline in egg intake and a slight reduction in diets with a high total lipid content, were found only in more developed regions.

Shifting obesity trends in Brazil

OBJECTIVE

To describe secular trends in obesity in various settings and socio-economic groups of the adult population of Brazil.

METHODS

Trend analysis of the prevalence of obesity in adults aged over 20 y (body mass index >/=30.0 kg/m2) applied to anthropometric and socio-economic data collected by three comparable household surveys undertaken in the two most populated Brazilian regions in 1975 (n=95,062), 1989 (n=15,585) and 1997 (n=10,680).

RESULTS

While previous trends (1975-1989) showed increasing obesity prevalence for all population groups except for men in rural areas, recent trends (1989-1997) have pointed to a much more complex picture where increases in obesity tend to be more intense in men than in women, in rural than in urban settings and in poorer than in richer families. Particularly notable was the fact that, in the recent period, obesity was actually reduced for women belonging to the upper income groups, especially in urban settings.

CONCLUSION

Earlier obesity trends in Brazil entirely agree with what has been described for both developed and developing countries where reliable secular trend information exists, but the 1989-1997 trend of a substantial reduction in the prevalence of obesity among upper income urban women (12.8-9.2%, or a 28% reduction), is unique in a developing country and, indeed, up to now has only been detected in Scandinavian populations. It is speculated that this declining obesity trend may be a result of an intense mass media work focused on combating a sedentary life style and promoting better food habits.

[Estimating the prevalence of height for age deficits based on the prevalence of weight for age deficits among Brazilian children]

INTRODUCTION

Anthropometry is frequently used for evaluating nutritional status of individuals and populations. In recent years, community surveys have been conducted by health professionals in various regions of Brazil with the objective of complementing the data obtained through nutritional surveillance programs. One important difficulty in conducting these assessments has been measuring height during visits to the homes of survey participants.

METHODS

Thirty-eight anthropometric surveys of Brazilian children aged up to 5 years using the National Center for Health Statistics (NCHS) reference were identified. The percentage of children with a Z-score below standard deviations was used to define deficits of weight for age and height for age.

RESULTS

Correlation between prevalences of height for age and weight for age deficits were examined. Due to the low prevalence of deficits in weight for height in all surveys, there was a strong correlation between weight for age and height for age at the population level. Approximately 90% of the height for age (H/A) variation was accounted for by that of weight for age (W/A).

CONCLUSIONS

Using the equation, (Prevalence H/A) = 0.74 + 2.34 (Prevalence W/A) -0.03 (Prevalence W/A)2 it is possible to estimate the prevalence of height deficits on the basis of prevalence of weight deficits. These results suggest that anthropometric surveys as conducted in Brazil, in the context of health services, can be simplified by measuring weight only, instead of both weight and height.

Preliminary characterization of a structural defect in homozygous sickled cell alpha spectrin demonstrated by a rabbit autoantibody

We have identified a rabbit autoantibody that strongly reacts with the core membrane skeleton of control red blood cells, and does not react with low- or high-density sickle cell core skeletons upon indirect immunofluorescence. Western blot analysis of red blood cell membrane proteins, utilizing this autoantibody, indicated no reactivity to any protein when SDS-PAGE was conducted in the presence of the reducing agent, dithiothreitol. However when SDS-PAGE was performed on control red blood cell membrane proteins separated in the absence of dithiothreitol, the autoantibody specifically reacted with a high molecular weight polypeptide (apparent Mr approximately equal to 310 kD) representing a DTT sensitive form of control alpha spectrin, which we refer to as alpha' spectrin. There was no staining of high density or low density sickle cell alpha or alpha' spectrin. This autoantibody should be an excellent tool for the fine mapping of structural change(s) in control vs. sickle cell alpha spectrin, and determination of whether the structural alteration effects spectrin dimer-tetramer interconversion and/or the spectrin-actin interaction. The modification in alpha spectrin, detected by this antibody, is very specific for homozygous SS alpha spectrin because sickle cell beta+ thalassemic alpha spectrin and sickle cell trait alpha spectrin react intensely with the autoantibody.

The efficacy of reducing agents or antioxidants in blocking the formation of dense cells and irreversibly sickled cells in vitro

We show that N-acetylcysteine (NAC) has the ability to cause statistically significant diminishment in the in vitro formation of irreversibly sickled cells (ISCs) at concentrations greater than 250 micromol/L. Other antioxidants, approved for human use (cysteamine, succimer, dimercaprol), were not efficacious. NAC had the ability to cause statistically significant conversion of ISCs formed in vivo back to the biconcave shape. NAC was also shown to reduce the formation of dense cells and increase the available thiols in beta-actin. We showed that diminishing reduced glutathione (GSH), by treatment with 1-chloro-2,4-dinitrobenzene, resulted in increased dense cells. We conclude the NAC blocks dense cell formation and ISC formation by targeting channels involved in cellular dehydration and beta-actin, respectively. The efficacy of NAC is probably due to its combined antioxidant activity and ability to increase intracellular GSH.

Patterns of intra-familiar distribution of undernutrition: methods and applications for developing societies

OBJECTIVE

To propose a method to assess patterns of intra-familiar distribution of undernutrition and apply it to different socioeconomic strata of the Brazilian population.

DESIGN

A large nationally representative cross-sectional anthropometric survey undertaken in 1989 is the primary source of information. Undernutrition was defined as body mass index (adults) and weight-for-age (children) below the 5th percentile of a healthy and non-malnourished reference population. Log-linear models were used to assess patterns of intra-familiar distribution of nutritional status in four income strata.

SUBJECTS

Two thousand, one hundred and seventy-four families composed by at least one child 6-36 month-old and his/her father and mother.

SETTING

All regions in Brazil.

RESULTS

Undernutrition was significantly associated among household members only for the 25% poorest families (P < 0.0001). In this group, the presence of undernutrition in the mother or the father increased 1.6-1.9 times the risk of undernutrition in the child and the presence of undernutrition in the father made it 2.7 times more frequent in the mother. The relatively small prevalence ratios suggest that even in extremely poor families only a small proportion of undernutrition could be attributed to common household determinants.

CONCLUSION

Our results are consistent with the hypothesis that in transitional societies undernutrition would appear as a global family problem only for those at the earlier stages of the nutrition transition. Policies and strategies to overcome undernutrition should take this fact into account.

The stage of nutrition transition in different Brazilian regions

The stage of nutrition transition in Brazil at the end of the 1980s was evaluated using the data from a nationwide cross-sectional anthropometry survey in Brazil in 1989 (Pesquisa Nacional sobre Saúde e Nutrição-PNSN). Comparable estimates of undernutrition and obesity were produced for children from 6 to 35 months old (n = 3,641), adult males from 20 to 64 years old (n = 14,235) and adult females from 18 to 64 years old (n = 15,669). Body Mass Index (kg/m2) was employed to assess both undernutrition and obesity in adults and weight-for-age (undernutrition) and weight-for-height (obesity) indices were used for children. The 5th and 95th centiles of the distribution of these indices in a reference population were used as limits for the diagnosis of undernutrition and obesity, respectively. Ordering the frequency of the problems in the population showed obesity in women and undernutrition in children to be the two main nutritional disorders in the country. These two problems are the most frequent in the urban population of the North, Northeast and Center-West regions, and in the Southeast and Center-West rural regions. Obesity leads among both adults and children in the urban areas of the Southeast and South regions, and in the rural South. Only in the rural Northeast, the poorest region in the country, undernutrition leads among children, men and women. This mosaic of situations determines the need for a complete reassessment of traditional nutrition policies and programs employed in the country.

[Prevention of anemia in the first year of life in health centers of Santo André, São Paulo]

The aim of this study was to evaluate the efficacy of an iron prophylactic supplementation program, in three health centers of Santo André, in São Paulo state. The prevalence of anemia was identified in a control group consisting of 201 children of 1 year old. The intervention group consisted of 308 children younger than 3 months, but 55% of them gave up during the survey. The mothers were instructed to give them daily prophylactic doses of iron sulfate (6 mg of iron/day) when they were 4 or 6 months old, according to the kind of breast-feeding. The mothers were also instructed about feeding and anemia and its risk to children's health. When the children were 12 months old, the diagnosis of anemia was made through dosage of hemoglobin concentration and the results were compared with those of the control group. It was verified that the 2 groups presented similar prevalences. It is important to realize that children with low frequency of visits to the health centers had prevalence of anemia significantly higher than those with high frequency. Some factors that possibly contributed to the result of the intervention are discussed.

Identification of the disulfide-linked peptide in irreversibly sickled cell beta-actin

We have previously demonstrated that the membrane skeletons of irreversibly sickled cells (ISCs) dissociate more slowly at 37 degrees C, in high ionic strength Triton X-100 buffer, than do the membrane skeletons of reversibly sickled cells or control erythrocytes [Shartava et al. (1995) J. Cell. Biol. 128, 805-818]. Furthermore, we demonstrated that the major cause of this slow dissociation was a single posttranslational modification in ISC beta-actin. Two sulfhydryl groups (Cys284 and Cys373) became inaccessible to thiol reagents because of this modification. We suggested the possibility that the modification was a disulfide bridge between Cys284 and Cys373 since the reducing agent dithiothreitol restored the sulfhydryl groups. In this article, we directly demonstrate the existence of the disulfide bridge between cysteine284 and cysteine373 in ISC beta-actin. We synthesized the associated ISC beta-actin tryptic cystine-peptide (KCF-CDVDIR), characterized it by HPLC, MS. and MSMS, and identified it in the tryptic digest of the ISC beta-actin. These results support our earlier suggestion that the oxidative change in ISC beta-actin is a major cause of the irreversible sickling phenomenon.

High density sickle cell erythrocyte core membrane skeletons demonstrate slow temperature dependent dissociation

We have previously demonstrated that slow dissociation of HDSS membrane skeletons in high ionic strength Triton X-100 buffer was related to a posttranslational modification in beta-actin, in which a disulfide bridge was formed between cysteine 284 and cysteine 373[Shartava et al: J Cell Bio 128:805, 1995]. These previous dissociation assays were limited to two homozygous (SS) sickle cell patients and a single temperature (37 degrees C). In the current work, we have expanded the SS subjects to 9 and have carried out dissociation assays at 0, 24, 30, 34, and 37 degrees C. At 0 degrees C there was limited dissociation of spectrin and actin from normal(AA), low density sickle cell(LDSS), and high density sickle cell (HDSS) core skeleton up to 24 hr. The first order rate constants for dissociation of spectrin, at 0 degrees C, was 0.030-0.035 x 10-4 sec-1 for AA,LDSS, and HDSS core skeletons. However at 24, 30, 34, and 37 degrees C the rate of dissociation of spectrin from HDSS core skeletons was significantly slower than the rate of dissociation from AA core skeletons. Having determined the first order rate constants for spectrin dissociation at these specified temperatures, we then asked whether dithiothreitol (DTT) would hasten the dissociation of core skeletons. The presence of DTT caused the rate of dissociation of the HDSS membrane skeleton to become statistically indistinguishable from the rate of dissociation of AA membrane skeletons. This is consistent with the suggestion that reversible thiol oxidation is responsible for the slow dissociation of the HDSS membrane skeleton.

A posttranslational modification of beta-actin contributes to the slow dissociation of the spectrin-protein 4.1-actin complex of irreversibly sickled cells

Irreversibly sickled cells (ISCs) remain sickled even under conditions where they are well oxygenated and hemoglobin is depolymerized. In our studies we demonstrate that triton extracted ISC core skeletons containing only spectrin, protein 4.1, and actin also retain their sickled shape; while reversibly sickled cell (RSC) skeletons remodel to a round or biconcave shape. We also demonstrate that these triton extracted ISC core skeletons dissociate more slowly upon incubation at 37 degrees C than do RSC or control (AA) core skeletons. This observation may supply the basis for the inability of the ISC core skeleton to remodel its shape. Using an in vitro ternary complex dissociation assay, we demonstrate that a modification in beta-actin is the major determinant of the slow dissociation of the spectrin-protein 4.1-actin complex isolated from the ISC core skeleton. We demonstrate that the difference between ISC and control beta-actin is the inaccessibility of two cysteine residues in ISC beta-actin to labeling by thiol reactive reagents; due to the formation of a disulfide bridge between cysteine284 and cysteine373 in ISC beta-actin, or alternatively another modification of cysteine284 and cysteine373 which is reversible with DTT and adds less than 100 D to the molecular weight of beta-actin.

The nutrition transition in Brazil

OBJECTIVE

To describe and analyse changes in child and adult nutritional status in Brazil during the past several decades.

DESIGN

Two large nationally representative cross-sectional anthropometric surveys undertaken in 1974 and 1989 are the primary source of information. Child nutritional status was described based on weight-for-age and weight-for-height indices using NCHS/WHO standards. Body mass index was employed to assess adult nutritional status.

SUBJECTS

27,960 children and 94,699 adults in 1974 and 5969 children and 23,544 adults in 1989.

SETTING

All regions in Brazil.

RESULTS

Undernutrition, although still relevant particularly in children from lower income families, is declining among adults and children of all economic strata. Concurrent increases in adult obesity have been occurring among all groups of men and women with a higher proportion of increase among lower income families. A profound change in the income-obesity relationship determines that in the most recent survey: (1) income and body mass index are inversely related among the 30% richest women; (2) a higher prevalence of female obesity (15.4%) occurs for the 40% middle-income group; and (3) the 30% poorest Brazilian women (9.7% prevalence) can no longer be considered to be protected from obesity.

CONCLUSION

Brazil is rapidly shifting from the problem of dietary deficit to one of dietary excess.