Biochemical markers and anthropometric profile of children enrolled in public daycare centers

OBJECTIVE

The nutritional status resultant from dietary habits along with socioeconomic conditions and the school environment are directly related to the individual's health condition not only in their childhood but also throughout adulthood. The aim of this study was to evaluate the effects of socioeconomic factors on the anthropometric profile and to analyze a probable association between this profile and biochemical markers in children attending public daycare centers.

METHODS

It is a transversal study developed in a probability sample of clusters of children from 6 months to 5 years old. Anthropometric and socioeconomic data were gathered at the CMEIs, questionnaires on the nutritional status were applied and blood was collected at the Family Health Units (USFs).

RESULTS

Female children are three times more likely to be underweight; in families with five members, it is 1/3 more likely that children of higher-educated parents are overweight. Among the results of the biochemical tests, hypervitaminosis A was a relevant aspect, positively correlating with copper (p=0.005) and zinc (p=0.008).

CONCLUSION

Therefore, since the influence of the family is an important predictor of overweight and its future outcomes related to nutritional deficiencies and inadequate dietary intake, educational interventions are vital as a way to pave the path to prevention.

Innovation results of IAM planning in urban water services

The requirement to provide urban water services continuously while infrastructures are ageing, imposes the need for increasingly sustainable infrastructure asset management (IAM). To achieve and maintain adequate levels of service, the AWARE-P IAM methodology has been applied in collaborative projects launched by the National Civil Engineering Laboratory, in partnership with IST (Technical University of Lisbon), Addition (software company) and several water utilities. The objective of these projects is to support urban water utilities in the development, implementation and maintenance of IAM plans. To guarantee the success of IAM planning, following the AWARE-P IAM methodology, utilities are required to: consider that the infrastructure has system behaviour and lifespan is indefinite and guarantee the full-alignment of IAM planning with organisation objectives. By analysing the strategic and tactical plans of participating utilities, the proposed methodology principles are discussed and supported. The main innovation results from the implementation of IAM planning are also presented and discussed, including the challenges of setting up an IAM process, together with the major benefits and drawbacks that come up when developing IAM plans. The results were demonstrated by the effective implementation of 16 strategic and 14 tactical IAM plans by the participating utilities.

Effect of platelet-rich plasma therapy associated with exercise training in musculoskeletal healing in rats

BACKGROUND

Muscle healing is a time-dependent process associated with an increase in the total amount of local collagen fibers. Platelet-rich plasma therapy (PRPT) associated with exercise may improve this healing process. The aim of this study was to demonstrate the regenerative effect of PRPT in association with exercise training on musculoskeletal healing.

METHODS

Male Wistar rats were submitted to an injury in the vastus lateralis muscle and randomly divided into 4 groups (n = 5/group): sedentary sham-operated (SSO); sedentary group submitted to PRPT (SPR); swim-trained (SWT); and swim-trained group submitted to PRPT (SWP). Serum lactate level was used to confirm the training protocol effectiveness to increase aerobic fitness. The collagen fiber concentration was measured by the polarization colors in picrosirius red-stained tissue sections.

RESULTS

Lactate levels decreased in both training groups (SWT and SWP; P < .05) after training (SWT: from 6.2 ± 0.44 to 4.7 ± 0.22 mmol/L; SWP: from 5.5 ± 0.99 to 4.0 ± 0.78 mmol/L). There were less type 1 collagen fibers in SWP group compared with other groups (SSO = 31.8 ± 10.3, SSP = 32.3 ± 13.5, SWT = 14.6 ± 13.4, SWP = 5.7 ± 4.7, P < .05), while there were more type 3 collagen fibers on SWP (SSO = 68.7 ± 9.8, SSP = 71.2 ± 12.2, SWT = 85.4 ± 13.4, SWP = 94.4 ± 4.6, P < .05) in the injured region.

CONCLUSION

Exercise in association with PRPT enhances the skeletal muscle-healing process.

Urban water infrastructure asset management - a structured approach in four water utilities

Water services are a strategic sector of large social and economic relevance. It is therefore essential that they are managed rationally and efficiently. Advanced water supply and wastewater infrastructure asset management (IAM) is key in achieving adequate levels of service in the future, particularly with regard to reliable and high quality drinking water supply, prevention of urban flooding, efficient use of natural resources and prevention of pollution. This paper presents a methodology for supporting the development of urban water IAM, developed during the AWARE-P project as well as an appraisal of its implementation in four water utilities. Both water supply and wastewater systems were considered. Due to the different contexts and features of the utilities, the main concerns vary from case to case; some problems essentially are related to performance, others to risk. Cost is a common deciding factor. The paper describes the procedure applied, focusing on the diversity of drivers, constraints, benefits and outcomes. It also points out the main challenges and the results obtained through the implementation of a structured procedure for supporting urban water IAM.

Assessing the environmental performance of urban wastewater systems using the INSA model: application to the Algés-Alcântara wastewater system, in Portugal

Although the application of complex integrated models to wastewater systems is useful, it is often difficult to implement and not always suitable for the design of new systems or for their rehabilitation. Integrated simple approaches that allow assessing the environmental performance of urban wastewater systems may be advantageous, especially during the initial phases of the system planning process. This paper presents an original, straightforward approach that can be used for planning, design and operation of urban wastewater systems. The INtegrated Simplified Approach (INSA) combines the concepts of performance indicators with mass balances and can be applied to wastewater systems as a management support tool, particularly in situations where there is lack of data, economic limitations or time constraints. The INSA was applied to the Algés-Alcântara wastewater system to evaluate its environmental performance and to simulate the individual or combined impact of the rehabilitation measures proposed, thus defining their priority. The results clearly indicate that, despite the investment already made upgrading the wastewater treatment plant (WWTP), the proposed interventions must be implemented to ensure an acceptable environmental performance of the system. In addition, the results demonstrate the significant pollution loads present in stormwater, frequently higher than the pollution loads discharged into receiving waters during dry weather.

Dietary fructose, fruits, fruit juices and glucose tolerance status in Japanese-Brazilians

BACKGROUND AND AIMS

Evidence suggests that fructose and sweetened beverages may be a risk factor for obesity and type 2 diabetes, but the role of sweetened fruit juices in glucose disturbances has been minimally explored. The aim of this study was to examine the association of total fructose, fresh fruit and sweetened fruit juice intake with glucose tolerance homeostasis in Japanese-Brazilians.

METHODS AND RESULTS

A total of 475 men and 579 women aged >or=30 years were evaluated in a cross-sectional population-based survey with a standardized protocol including a 2-h oral glucose tolerance test (WHO criteria). Habitual food consumption was obtained using a validated food frequency questionnaire for Japanese-Brazilians. After adjustments for potential confounding variables, the odds ratio (OR; 95%CI) for impaired glucose tolerance was 2.1 (1.0-4.5; P for trend=0.05) for the highest as compared to the lowest tertile intake of total fructose and 2.3 (1.1-5.1; P for trend=0.05) for the highest as compared to the lowest tertile intake of sweetened fruit juices.

CONCLUSION

Our results showed that high intakes of dietary fructose and sweetened fruit juices, but not whole fresh fruits, were associated with impaired glucose tolerance among genetically susceptible individuals.

Direct detection of Mycobacterium bovis in bovine lymph nodes by PCR

Thirty-five lymph node samples were taken from animals with macroscopic lesions consistent with Mycobacterium bovis infection. The animals were identified by postmortem examination in an abattoir in the northwestern region of state of Paraná, Brazil. Twenty-two of the animals had previously been found to be tuberculin skin test positive. Tissue samples were decontaminated by Petroff's method and processed for acid-fast bacilli staining, culture in Stonebrink and Lowenstein-Jensen media and DNA extraction. Lymph node DNA samples were amplified by PCR in the absence and presence (inhibitor controls) of DNA extracted from M. bovis culture. Mycobacterium bovis was identified in 14 (42.4%) lymph node samples by both PCR and by culture. The frequency of PCR-positive results (54.5%) was similar to that of culture-positive results (51.5%, P > 0.05). The percentage of PCR-positive lymph nodes increased from 39.4% (13/33) to 54.5% (18/33) when samples that were initially PCR-negative were reanalysed using 2.5 microl DNA (two samples) and 1 : 2 diluted DNA (three samples). PCR sensitivity was affected by inhibitors and by the amount of DNA in the clinical samples. Our results indicate that direct detection of M. bovis in lymph nodes by PCR may be a fast and useful tool for bovine tuberculosis epidemic management in the region.

[ENDEF and PNSN: trends in physical growth of Brazilian children]

This paper compares the results of two nationally representative nutritional surveys carried out in Brazil: the "Estudo Nacional de Despesa Familiar (ENDEF)" (National Survey on Household Expenses), conducted in 1974-77, and the "Pesquisa Nacional de Saúde e Nutrição (PNSN)" (National Survey on Health and Nutrition), conducted in 1989. The findings point to a reduction of more than 60% in the prevalence of undernutrition, as evaluated by anthropometric parameters. The results from regional surveys and the trends in infant mortality throughout the 1970s and 1980s are consistent with the improvements in nutritional status. Less striking reductions in undernutrition rates were observed in certain regions of the country (e.g., the North and Northeast), where prevalences were higher in the 1970s, resulting in a widening of regional differences. The improvements in child nutrition are attributed to moderate increases in family income, particularly in the 1970s, and to the expansion of sanitation, public health, and educational services, as well as food supplementation programs, which were also favored by a fall in fertility levels. The authors call attention to the fact that the lack of clear-cut indications of economic recovery in Brazil recently, coupled wih cuts in government budgets for social services and the persistence of inequality in income distribution, among other factors, make it unlikely that improvements in nutritional status, as observed in the 1970, will take place in the upcoming years.

Long-term population isolation in the endangered tropical tree species Caesalpinia echinata Lam. revealed by chloroplast microsatellites

Habitat fragmentation represents the single most serious threat to the survival of tropical ecosystems. In formulating strategies to counteract the detrimental effects of fragmentation, knowledge of the levels and patterns of genetic diversity within and between natural populations is vital to the establishment of any conservation programme. We utilized polymorphic chloroplast microsatellite markers to analyse genetic diversity in populations of the endangered tropical tree Caesalpinia echinata Lam. representing the entire extant range of the species. Levels of within-population diversity were low, with only two of seven populations studied displaying any variation. The vast majority of the genetic variation was partitioned between geographical regions (36%) and between populations within regions (55%). These levels of genetic structuring, coupled with a calculated pollen-to-seed flow ratio of approximately 6.7:1, suggest that there has been little gene flow between the three major geographical regions over an extended period. Thus, the current tripartite distribution of the species is more consistent with the existence of separate glacial refugia, rather than reflecting any anthropogenic effects.

[Study of the infection and morbidity of Chagas' disease in municipality of João Costa: National Park Serra da Capivara, Piauí, Brazil]

In order to investigate aspects of the infection and morbidity of Chagas' disease in the municipality of João Costa, Piauí State, Brazil, we carried out a serological survey to detect anti-Trypanosoma cruzi antibodies in 2,080 individuals, by indirect immunofluorescence, indirect hemagglutination and ELISA. A total of 189 seropositive and 141 seronegative patients were evaluated by anamnesis, physical exam and electrocardiogram (EKG). The parasitaemia of 106 chagasic patients was evaluated by indirect xenodiagnosis and PCR (polymerase chain reaction). The total seropositivity was 9.8%, with intervals of 0.5% in patients younger than 10 years old, and 39.4% among patients older than 59 years old, independently of the sex. The PCR and xenodiagnosis were positive, respectively in 74.5% and 15.1% of the seropositive patients (p < 0.05). The rate of abnormal EKG was 41.3% in chagasic and 15.6% in non-chagasic patients (p < 0.05). In spite of the high prevalence of infection in the investigated population, the low rate of seropositivity among children is indicative of a possible decrease of the active transmission mediated by triatomines. The high proportion of the chagasic component on the cardiopathy prevalence is indicative of the high morbidity of Chagas' disease in the studied region.

Parasite persistence in treated chagasic patients revealed by xenodiagnosis and polymerase chain reaction

Polymerase chain reaction (PCR) was compared with xenodiagnosis performed 20 years after trypanocidal chemotherapy to investigate parasite clearance. Eighty-five seropositive individuals for Chagas disease presenting a positive xenodiagnosis were treated with specific drugs; 37 in the acute phase and 48 in the chronic phase. Fifteen chronic asymptomatic patients received a placebo. Treatment in the acute phase led to PCR negative results in 73% of the cases, while xenodiagnosis was negative in 86%. In the chronic phase, PCR was negative in 65% of the patients and 83% led to xenodiagnosis negative results. Regarding the untreated group (placebo), 73% gave negative results by xenodiagnosis, of which 36% were positive by PCR. Individuals that were considered seronegative (n=10), presented unequivocally negative results in the PCR demonstrating the elimination of parasite DNA. Seventeen individuals had their antibodies titers decreased to such a level that the final results were considered as doubtful and 16 of them presented negative PCR. The molecular method represents a clear advantage over conventional techniques to demonstrate persistent infections in Chagas disease patients that underwent chemotherapy.

Structural studies on fucoidans from the brown seaweed Sargassum stenophyllum

The brown seaweed Sargassum stenophyllum biosynthesizes two different sets of fucoidans. One of them is characterized by higher percentages of glucuronic acid and fewer sulfate groups, which are situated on different sugar units. alpha-L-Fucose was the major component but other sugars like beta-D-galactose, beta-D-mannose, alpha-D-glucuronic acid, alpha-D-glucose and beta-D-xylose were also in substantial amounts. Fucoidans from the other set contain small amounts of alpha-D-glucuronic acid and high percentages of sulfate groups, which are concentrated on the fucose residues, with only fucose and galactose as major components. Structural studies of one fucoidan from each set suggest that these products have a general basic structure that has a formal resemblance to that of the fucosylated chondroitin sulfates from the body wall of sea cucumbers, namely, a linear core (formed mainly by (1-->6)-beta-D-galactose and/or (1-->2)-beta-D-mannose units) with branched chains of 'fucans' (formed by (1-->3) and/or (1-->4)-alpha-L-fucose, (1-->4)-alpha-D-glucuronic acid, terminal beta-D-xylose and, sometimes, (1-->4)-alpha-D-glucose). In fucoidans from the second set, the 'core' is reduced to short galactan chains.

Genetic differentiation of Euterpe edulis Mart. populations estimated by AFLP analysis

Heart-of-palm (Euterpe edulis Mart.) is a wild palm with a wide distribution throughout the Atlantic Rainforest. Populations of E. edulis represent important renewable natural resources but are currently under threat from predatory exploitation. Furthermore, because the species is indigenous to the Atlantic Rainforest, which is located in the most economically developed and populated region of Brazil, social and economic pressures have devastated heart-of-palm forests. In order to estimate the partitioning of genetic variation of endangered E. edulis populations, 429 AFLP markers were used to analyse 150 plants representing 11 populations of the species distribution range. Analysis of the genetic structure of populations carried out using analysis of molecular variance (AMOVA) revealed moderate genetic variation within populations (57. 4%). Genetic differentiation between populations (FST = 0.426) was positively correlated with geographical distance. These results could be explained by the historical fragmentation of the Atlantic coastal region, together with the life cycle and mating system. The data obtained in this work should have important implications for conservation and future breeding programmes of E. edulis.

Weight gain in adulthood and risk of developing glucose tolerance disturbance: a study of a Japanese-Brazilian population. Japanese-Brazilian Diabetes Study Group

We examined the data from 530 subjects enrolled in a survey on the prevalence of diabetes in a Japanese-Brazilian population aged 40-79 years. Past self-reported and current weight values were analysed. Student t test was used to compare anthropometric measures between subjects with and without disturbance of glucose tolerance (DGT), hypertension and dyslipidemia. Point and interval estimates of the weight at 20 years-, age- and sex-adjusted odds ratios (OR) were obtained by logistic regression analysis to evaluate the relationship between these diseases and the percent weight gain. Subjects with DGT, hypertension or dyslipidemia tended to have higher BMI during adulthood and to gain more weight in a shorter interval of time. Also, they presented higher waist-to-hip ratio and plasma glucose and worse lipid profile. OR were consistent with associations between chronic diseases and percent weight gain. Trend test of OR indicated that the risk of developing DGT alone or combined with hypertension and abdominal obesity increased 2% and 15% by percent unit of gained weight, respectively, as compared with those subjects with stable weight. Weight gain and the rate by which this occurs during lifetime may confer increased risk of chronic diseases. We suggested that preventive measures against obesity, i.e. the maintenance of healthy body weight lifelong, are necessary to minimize the occurrence of these diseases, also among migrant populations such as the Japanese-Brazilians.

Paleoparasitology of Chagas disease revaled by infected tissues from Chilean mummies

Mummified tissues were sampled from bodies stored at the Museo Arqueologico de San Pedro de Atacama, northern Chile, dated from 2000 years BP-1400 AD, and Trypanosoma cruzi DNA was recovered using polymerase chain reaction (PCR) methodology. Amplification of the conserved region of the minicircle molecule of T. cruzi was achieved in four of the six samples tested. Amplified products corresponding to genetic fragments of the parasite were tested by hybridization experiments with positive results for T. cruzi specific molecular probe. The origin and dispersion of T. cruzi human infection is discussed as well as the molecular paleoparasitological approach, and what it may represent in an evolutionary perspective.

[Development of a quantitative questionnaire of food intake in japanese immigrants and their descendants residents in Sao Paulo, Brazil]

The present study describes the development of a questionnaire to assess usual frequency and quantity of food and nutrient intake by people of Japanese descent living in São Paulo, Brazil. Both the food list and appropriate serving sizes for food items from the Food Frequency Questionnaire (FFQ) were selected from a cross-sectional assessment of diet in a random sample of Japanese immigrants living in the city of São Paulo (first- and second-generations, n = 166), aged 45-70 years, using self-administered three-day food records. We used the food records to select food items on the basis of their contribution to total population intake of relevant foods and nutrients. Criteria for grouping separate foods included similarity in nutrient content per usual serving and the importance of a particular food (e.g., typical Japanese foods). Four portion sizes were presented: small, medium, large, and extra-large. We examined the frequency distribution of equivalent-gram weights of each selected food and identified the four serving sizes in the distribution. The quantitative FFQ was designed with 129 food groups and exact frequencies of intake. Instructions for self-reporting and applications of the method for epidemiological use are discussed.

[Outbreak of American cutaneous leishmaniasis in Canoa, Santo Amaro, Bahia, Brazil]

An outbreak of American cutaneous leishmaniasis (ACL) was detected in the village of Canoa in 1993. A prospective observational study was outlined to determine the frequency rates and to clinically characterize the disease. A total of 555 people were followed up. There were 29 cases of ACL, 11 cases of probably previous ACL (scars) and 529 healthy individuals. Of these 529 individuals, 65 had a positive Montenegro reaction without any present or past evidence of leishmaniasis. The prevalence of ACL during the two years was 5.2% (29/555). The leishmania involved was Leishmania braziliensis and the vector, Lutzomyia intermedia. Evidence of infection was detected in dogs and horses. The high frequency of the disease among children under ten years, the similar sex distribution of cases and a component of familial aggregation suggest a peri- or intra-domiciliary transmission.

A laboratory cage for foster nursing newborn mice

We describe a cage to be used for foster nursing in order to guarantee that original mother's colostrum is not ingested by the newborn mice. A common (30.5 cm x 19.5 cm x 12.0 cm) mouse cage was fitted with a wire net tray with a mesh (1 cm x 1 cm), which divides the cage into an upper and a lower compartment. Mice born to females placed in the upper compartment pass through the mesh and fall into the lower compartment, where another lactating female with one or two of its own pups are. Of a total of 28 newborn mice of C3H/Hc and Swiss strains, 23 were successfully fostered. Important observations are presented to show that this is a valuable alternative for foster studies without great suffering on the part of the female.

Nitric oxide-induced apoptotic cell death in the acute phase of Trypanosoma cruzi infection in mice

Production of gamma-interferon (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) in Trypanosoma cruzi-infected mice results in the activation of inducible nitric oxide synthase (iNOS) and in elevated nitric oxide (NO) synthesis, which is important for the macrophage trypanocidal activity. However, NO has been shown to be involved in suppression of host immunity. In the present investigation, we studied the role of NO in inducing apoptosis in cells from BALB/c mice acutely infected by T. cruzi. Splenocytes from infected mice had a reduced cell viability and elevated levels of spontaneous apoptosis after 48 h in culture. Inhibition of NO production by the addition of the L-arginine analog NG-monomethyl-L-arginine (L-NMMA), or of monoclonal antibodies (mAbs) to IFN-gamma or TNF-alpha spleen cells, partially restored cell viability and caused a decrease in the levels of apoptosis in splenocytes from infected animals. Spleen cells from T. cruzi-infected mice had an apoptosis-specific pattern of internucleosomal DNA fragmentation which was most marked at the ninth day after infection when the plasma NO levels and parasitemia were increased. Treatment of infected mice with L-NMMA, anti-TNF-alpha, or anti-IFN-gamma mAbs caused reduction of both NO production and the amount of apoptotic cells, suggesting that NO plays a direct role in the induction of apoptosis in vivo. Taken together, these data support the hypothesis that, as well as modulating immunosuppression, NO produced by IFN-gamma and TNF-alpha activated macrophages plays a role in apoptosis induction during the acute phase of experimental T. cruzi infection.

Dietary patterns in Japanese migrants to southeastern Brazil and their descendants

This paper describes the dietary patterns of people of Japanese ancestry living in São Paulo, Brazil. Two cross-sectional surveys using a food frequency questionnaire (in 1989 and 1995) and self-administered three-day food record (only in 1995) were carried out in randomly chosen first-generation (Japan-born) and second-generation (Brazil-born) Japanese living in the city of São Paulo (n = 166), aged 40-69 years at the time of the first survey (1989). Daily intake of rice, bread, milk, fruits and coffee, and infrequent consumption of pork, green tea, black tea, tsukemono (pickled vegetables), seaweed and mushrooms were reported. The mean (+/- standard deviation) daily proportions of energy from fat among Japan-born participants were 27.2 +/- 6.7% for men and 26.2 +/- 6.7% for women. The respective figures for Brazil-born Japanese were 30.1 +/- 7.4% and 29.5 +/- 6.4%. These values were quite close to recent estimates for the general Brazilian population in metropolitan areas (about 30%), but seem to be higher than available data from Japan (25.3%). Dietary changes in this migrant population are discussed with focus on nutrients currently implicated in the etiology of major chronic diseases.

PCR-based diagnosis for Chagas' disease in Bolivian children living in an active transmission area: comparison with conventional serological and parasitological diagnosis

A large field study has been performed in the Cochabamba region of Bolivia with the aim of comparing the polymerase chain reaction (PCR) with other diagnostic methods for Chagas' disease. The amplification of Trypanosoma cruzi-specific kinetoplast DNA sequences in blood samples was compared with classical serological methods, specific IgM detection and direct parasite visualization for 268 school children in a single village where Chagas' disease transmission is active. Of 113 children positive by classical serology or buffy coat examination, 106 were detected by PCR (sensitivity: 93.8%). We did not observe any significant difference of PCR sensitivity between initial (IgM and/or buffy coat positive) and indeterminate stage (only IgG positive) patients. Among the remaining 155 children unconfirmed as chagasic (who were either only IgM positive, IgG-, IgM-, and buffy coat-negative) only 1 case was PCR positive. This case may be due to DNA contamination, or to a very recent infection not detected otherwise, or to specific immune depression. These results show that PCR is a very sensitive parasitological test for Chagas' disease in active transmission regions. The future follow-up of the possibly infected patients who were only IgM-positive should clarify the interest of PCR and IgM tests in the detection of starting infections.

Interleukin-12 mediates resistance to Trypanosoma cruzi in mice and is produced by murine macrophages in response to live trypomastigotes

Host resistance to infection by Trypanosoma cruzi is dependent on both natural and acquired immune responses. During the first week of infection in mice, NK cell-derived gamma interferon (IFN-gamma) is involved in controlling intracellular parasite replication, mainly through the induction of NO biosynthesis by activated macrophages. Interleukin-12 (IL-12) has been shown to be a powerful cytokine in inducing IFN-gamma synthesis by NK cells, as well as in mediating resistance to different intracellular protozoa. We have therefore studied the ability of T. cruzi to elicit IL-12 synthesis by macrophages and the role of this cytokine in controlling parasite replication during acute infection in mice. Our results show that macrophages cultured in the presence of live trypomastigote forms (but not epimastigotes) release IL-12 that can induce IFN-gamma production by normal spleen cells. IL-12 was detected in as little as 12 h after the addition of the trypomastigotes, and the level of IL-12 peaked at 48 h after the initial macrophage-parasite incubation. The addition of anti-IL-12 monoclonal antibody to macrophage-trypomastigote supernatants dose-dependently inhibited IFN-gamma production by naive splenocytes. Finally, the in vivo role of IL-12 in resistance to infection by T. cruzi was analyzed. Mice treated with anti-IL-12 monoclonal antibody had significantly increased parasitemia and mortality in comparison with those of control infected mice treated with control antibody. Together, these results suggest that macrophage-derived IL-12 plays a major role in controlling the parasitemia in T. cruzi-infected mice and that the animal's resistance during the acute phase of infection may, at least in part, be a consequence of postinfection levels of IL-12.

Rapid epidemiologic assessment of breastfeeding practices: probit analysis of current status data

We describe the use of probit analysis to estimate breastfeeding indicators from current status epidemiological data. A health centre-based sample of 2411 children aged 0-1 year was investigated in Santo Andre, a large town in the Metropolitan Area of Sao Paulo, southeastern Brazil. Mothers were interviewed during routine pediatric consultations and asked about their current infant feeding practices. Probit regressions were calculated by a public-domain microcomputer programme written by one of us. The median duration of total (i.e. exclusive plus partial) breastfeeding in this children's sample, estimated as 108.8 days (95 per cent confidence interval: 95.5-123.2 days), is close to that recently reported in the city of Sao Paulo and nearby towns. However, the median duration of exclusive breastfeeding (28.9 days, 95 per cent CI: 17.9-38.3 days) is rather short when compared to recent estimates from this same region. Despite the nationwide efforts for promotion of exclusive breastfeeding, only 14 per cent (95 per cent CI: 12.3-17 per cent) of the infants were still being exclusively breastfed by 120 days of age. Therefore, a key feature of breastfeeding practices in this population sample, namely, the early introduction of supplementary foods, was identified by using simplified methods of data collection and analysis. This communication suggests that probit analysis of current status data may be further explored as a method for rapid epidemiologic assessment of breastfeeding practices.

Dietary iron supplementation does not aggravate experimental malaria in young rats

The hypotheses that iron-deficient hosts are less susceptible to severe malaria and that iron supplementation aggravates infection have been supported by some clinical and experimental evidence. In the present study, the course of Plasmodium berghei infection was monitored in an experimental model of dietary iron deficiency and iron supplementation. Weanling Wistar rats were fed purified diets with different iron concentrations: 20 mg/kg (Group D, n = 24), 50 mg/kg (Group N, n = 24) and 100 mg/kg (Group S, n = 12). After 15 d, rats from Group D were anemic (mean hemoglobin 81 g/l). The next day, 12 rats from Group D (thereafter Group DS) and 12 rats from Group N (thereafter Group NS) were transferred to the same iron-supplemented diet as in Group S, whereas the remaining animals (Groups D, N and S) were maintained on the original diets for further 14 d. At that time, 9 rats from each group were inoculated intraperitoneally with 10(6) erythrocytic parasites (P. berghei ANKA strain), whereas 3 rats from each group remained as noninfected controls. All animals were killed 14 d after inoculation, when significantly lower levels of hemoglobin, serum iron and percent transferrin saturation were found in infected animals from Group D compared with all other groups. However, the time course of parasitemias was similar in all groups. These data indicate that the development of P. berghei was neither suppressed by iron deficiency nor enhanced by iron supplementation in this model. Furthermore, iron repletion during infection did produce a noticeable improvement of hematological variables in previously iron-deficient animals.

Tumor necrosis factor alpha mediates resistance to Trypanosoma cruzi infection in mice by inducing nitric oxide production in infected gamma interferon-activated macrophages

Cell invasion by Trypanosoma cruzi and its intracellular replication are essential for continuation of the parasite life cycle and for production of Chagas' disease. T. cruzi is able to replicate in nucleated cells and can be killed by activated macrophages. Gamma interferon (IFN-gamma) is one of the major stimuli for the activation of macrophages and has been shown to be a key activation factor for the killing of intracellular parasites through a mechanism dependent upon nitric oxide (NO) biosynthesis. We show that although the addition of exogenous tumor necrosis factor alpha (TNF-alpha) does not potentiate the trypanocidal activity of IFN-gamma in vitro, treatment of resistant C57BI/6 mice with an anti-TNF-alpha monoclonal antibody increased parasitemia and mortality. In addition, the anti-TNF-alpha-treated animals had decreased NO production, both in vivo and in vitro, suggesting an important role for TNF-alpha in controlling infection. In order to better understand the role of TNF-alpha in the macrophage-mediating killing of parasites, cultures of T. cruzi-infected macrophages were treated with an anti-TNF-alpha monoclonal antibody. IFN-gamma-activated macrophages failed to kill intracellular parasites following treatment with 100 micrograms of anti-TNF-alpha. In these cultures, the number of parasites released at various time points after infection was significantly increased while NO production was significantly reduced. We conclude that IFN-gamma-activated macrophages produce TNF-alpha after infection by T. cruzi and suggest that this cytokine plays a role in amplifying NO production and parasite killing.

Trypanosoma cruzi: parasite detection and strain discrimination in chronic chagasic patients from northeastern Brazil using PCR amplification of kinetoplast DNA and nonradioactive hybridization

Blood samples from 172 individuals from northeastern Brazil were subjected to PCR amplification of Trypanosoma cruzi-specific kDNA sequences. This method enabled us to detect parasite DNA in 21 of 47 patients that were serologically positive. In addition, 1 patient that gave doubtful results with chagasic serology was confirmed as positive by PCR. We applied the same PCR detection method to the feces of wild triatomines captured in the same region, obtaining three positive results that were confirmed by microscopic examination. The 25 amplified products obtained in this study were then reamplified with primers that gave a final amplicon containing sequences from the most variable region of kDNA minicircles. These were used as probes in hybridization experiments aimed at defining the degree of relatedness between the strains infecting humans and insects based on kDNA homologies. We found that the amplification products from the three triatomines were related and showed no cross-hybridization with those obtained from human infections. Eight amplified products from human infections showed no cross-hybridization and did not hybridize with products from other patients. This indicates that the strains of T. cruzi circulating in the region present a high level of genetic heterogeneity. Finally, a number of amplified products hybridized with amplicons that did not hybridize with each other, indicating that infections with a parasite population presenting a mixed kDNA content (either due to different strains of T. cruzi or to a hybrid parasite) are a more frequent event than previously thought.

Dengue type 2 outbreak in the south of the state of Bahia, Brazil: laboratorial and epidemiological studies

During March 1994 cases of a exanthematic acute disease were reported in the municipalities of Itagemirim, Eunápolis and Belmonte, state of Bahia. Dengue fever was confirmed by serology (MAC-ELISA) and by dengue virus type 2 isolation, genotype Jamaica. Signs and symptoms of classic dengue fever were observed with a high percentual of rash (73.8%) and pruritus (50.5%). Major haemorrhagic manifestations were unfrequent and only bleeding gum was reported. Dengue virus activity spreaded rapidly to important tourism counties like Porto Seguro, Ilhéus, Santa Cruz de Cabrália, Prado, Alcobaça and others, representing a risk for the spreading of dengue virus into the country and abroad.

Polymerase chain reaction detection of Trypanosoma cruzi in human blood samples as a tool for diagnosis and treatment evaluation

Trypanosoma cruzi specific sequences were amplified by the polymerase chain reaction from total blood of human chagasic patients and normal individuals. A 330 bp fragment originating from kinetoplast DNA was specifically detected in most chagasic individuals. We tested the sensitivity and specificity of this method in normal and affected individuals attending the Evandro Chagas Hospital, Rio de Janeiro. The results of these tests were compared with serological diagnosis performed using standard techniques, and in some cases with xenodiagnosis. We found that none of the serologically negative individuals gave any specific amplification product, whereas 55 out of 61 patients previously serodiagnosed as chagasic were positive using the PCR method (sensitivity: 90%). Xenodiagnosis, which is currently considered to be the most sensitive parasitological technique for Chagas' disease diagnosis, detected only 12 out of 28 serologically positive patients (sensitivity: 43%). The usefulness of the PCR method was further investigated with chagasic patients who had received anti-parasite treatment with benznidazole. It has always been difficult to evaluate the incidence of cure in such cases by serology, since a humoral response against T. cruzi antigens may remain for years even in the absence of the parasite. We observed a positive amplification result in only 9 out of 32 treated patients who remained reactive when tested using classical serology. These observations suggest that PCR is the most sensitive technique available for direct detection of T. cruzi in chagasic patients and that it can be a very useful instrument for the follow-up of patients after specific treatment.

High correlation between Chagas' disease serology and PCR-based detection of Trypanosoma cruzi kinetoplast DNA in Bolivian children living in an endemic area

The detection of Trypanosoma cruzi kinetoplast DNA by polymerase chain reaction (PCR) amplification is a potentially powerful tool for the parasitological diagnosis of Chagas' disease. We have applied this technique in a field situation in Bolivia, where 45 children from a primary school were subjected to serological testing, buffy coat analysis and PCR diagnosis. 26 of the 28 serology-positive individuals were also positive by PCR. In addition, two serology-negative children gave a positive result by PCR, including one who was positive in the buffy coat test. These results suggest that PCR detection of T. cruzi DNA in blood can be a very useful complement to serology in Chagas' disease diagnosis in Bolivia.

Use of a simplified polymerase chain reaction procedure to detect Trypanosoma cruzi in blood samples from chronic chagasic patients in a rural endemic area

The feasibility of using DNA amplification by the polymerase chain reaction (PCR) for specific detection of Trypanosoma cruzi in human blood specimens was investigated. One hundred blood samples were collected in an endemic area of Minas Gerais, Brazil. They were submitted to DNA extraction and PCR amplification with kinetoplast DNA-specific primers using a simplified boiling procedure that linearized most minicircle molecules without the aid of chemical reagents. Samples that gave negative results were checked for possible inhibition of amplification using primers derived from a human-specific sequence, and those showing some level of inhibition were retested after a new DNA extraction. Of 86 patients previously diagnosed as chagasic by serologic techniques, 83 were positive in our PCR test (sensitivity = 96.5%), including all the xenodiagnosis-positive patients and 21 (87.5%) of 24 xenodiagnosis-negative individuals. In addition, four of six patients with doubtful serologic results were confirmed as positive by PCR. Our results suggest that the PCR may be a useful complement to serology in the diagnosis of Chagas' disease, and that it is the most powerful technique available for parasite detection in patients with chronic disease.

Intervenções nutricionais na anemia ferropriva

O objetivo deste estudo de revisão bibliográfica é fornecer subsídios para o planejamento e avaliação de medidas de combate à anemia ferropriva. A necessidade de intervenções para o controle da prevalência da anemia ferropriva deve ser determinada pela magnitude da defi ciência nutricional e pelo conhecimento de seus efeitos na qualidade de vida, morbidade e mortalidade. A abordagem mais usual é fornecer ferro suplementar a gestantes, nutrizes e lactentes em programas de assistência primária à saúde, reconhecidamente os grupos de maior vulnerabilidade. A fortificação de alimentos e orientações sobre modificações da dieta representam medidas complementares e devem ser incrementadas.

Anaemia, iron deficiency and malaria in a rural community in Brazilian Amazon

OBJECTIVE

To assess the incidence of anaemia, iron deficiency and malaria in a malaria-endemic community.

DESIGN

Three consecutive cross-sectional surveys (A, B and C) of the whole population made at 6-month intervals and malaria surveillance between the surveys.

SETTING

Urupá, a rural community in Western Brazilian Amazon.

SUBJECTS

133 people of all age groups present in at least two cross-sectional surveys.

INTERVENTIONS

Anaemic patients received ferrous sulphate during 3 months. Patients parasitized by intestinal nematodes were given mebendazole and parasitologically proven Plasmodium falciparum and P. vivax malaria attacks were treated with quinine or chloroquine plus primaquine.

RESULTS

Anaemia (haemoglobin concentrations [Hb] below the cut-off values proposed by the World Health Organization) was diagnosed in respectively 10.0% (13 of 130) subjects in survey A, 9.2% (10 of 109) in B and 29.7% (27 of 91) in C. Depleted iron stores [serum ferritin (SF) < 12 micrograms/l] were detected in 10.0% subjects in survey A, 10.1% in B but in only 8.8% subjects in survey C. Concomitant anaemia and low SF was detected in 5.4% subjects in survey A, 3.7% in B and 6.6% in C. Mean Hb from anaemic patients diagnosed and treated during the study (n = 17) raised 1.2 g/dl after iron therapy and most of them (13 of 17, 76.5%) became non-anaemic. The highest malaria transmission was observed between surveys B and C. People who suffered at least one malaria attack during this period (27 of 63) were at a slightly greater risk of subsequent anaemia (odds ratio = 2.85, 95% confidence interval 0.81-10.28).

CONCLUSIONS

Both malaria and iron deficiency could be considered as important causes of anaemia in this population.

SPONSORSHIP

Supported by grants from the UNDP/World Bank/World Health Organization Special Programme for Research and Training in Tropical Diseases (no. 890245), the Ministére des Affaires Etrangeres, France, and from the Fundação de Amparo à Pesquisa do Estado de São Paulo (no. 92/1336-4). M.A.C. was supported by a doctoral fellowship from the Conselho Nacional de Desenvolvimento Científico e Tecnológico.

Effect of dietary iron on the course of Plasmodium berghei malaria in young rats

Clinical and experimental evidence suggests that iron-deficient hosts are less susceptible to severe malaria and that iron supplementation aggravates infection. In the present study, 60 weanling Wistar rats were fed standard diets with different iron concentrations: 21 mg/kg (group 1), 45 mg/kg (group 2) and 113 mg/kg (group 3). Ferrous sulfate (FeSO4 x 7H2O) was added to the normal-iron and iron-supplemented diets (groups 2 and 3, respectively). Data are reported as mean +/- SEM. After 16 days of regimen, eight rats from each group were killed to measure serum iron concentration (SI) and transferrin saturation capacity (TSC). At this moment, rats from group 1 were underweight and their dietary intake was significantly lower than that of animals from the other groups. Severe iron deficiency (SI = 49.2 +/- 4.5 micrograms/100 ml and TSC = 8.3 +/- 0.7%) was observed in rats from group 1, while the animals from the other groups were iron-sufficient (group 2: SI = 186.5 +/- 28.5 micrograms/100 ml and TSC = 27.3 +/- 3.4%; group 3: SI = 137.3 +/- 18.2 micrograms/100 ml and TSC = 21.3 +/- 2.3%). Nine animals from each group were then infected with the malaria parasite Plasmodium berghei, whereas three animals from each group were used as noninfected controls. Parasitemias (% of infected red blood cells) peaked 7 days post-infection in animals from groups 2 and 3 (mean values of 2.4% and 1.7%, respectively), but in animals from group 1 parasitemias increased until the 9th day post-infection (mean at peak, 2.3%) and parasite clearance was significantly slower than in the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[Anemia in a population from an endemic area of malaria, Rondônia (Brazil)]

With the purpose of describing the prevalence rate of anaemia among inhabitants of a malaria endemic area--Candeias district, a periurban locality near Porto Velho, in Rondônia State, Brazilian Amazon Basin--a random population sample comprehending 1,068 individuals of all age groups (14.1% of the total population) was screened for anaemia (measurement of blood haemoglobin concentration) and malaria (Giemsa-stained thick-smear microscopy). Two-hundred and ninety-nine individuals (28.0% of the sample) were found to be anaemic, using the cut-off haemoglobin values proposed by the World Health Organization for each age group. Highest prevalence rates were found among children with ages varying from 6 months to 1 year (70.0%) and from 1 to 6 years (38.4%), as well as in pregnant women (41.2%, 7/17) and malaria patients (44.4%, 8/18). Parasitological stoll examinations were made on a voluntary sample of 476 individuals (44.6% of the sample population); of these, 118 (26.8%) were positive. Eggs of Ascaris lumbricoides, the most frequent intestinal parasite in this population sample, was detected in 67 stool samples (14.1%); only 27 patients (5.7%) eliminated Ancylostomidae eggs. In this voluntary sample, no significant difference in anaemia prevalence rates between parasite carriers and non-parasited individuals was detected. On the other hand, the more recent the last malarial episode referred to by the patients, the lighter prevalence rate of anaemia in individuals above the age of 14 years. The role played by malaria as an underlying cause of anaemia in Candeias district inhabitants, particularly in the economically active age group, is further discussed.

Nutritional status of Brazilian children: trends from 1975 to 1989

The prevalence of malnutrition among under-5-year-olds in Brazil fell by more than 60% between 1975 and 1989. The benefits were smaller for population strata that were more affected by malnutrition in the 1970s, i.e., children from the North and North-east regions and those from poor families in general. Regional and socioeconomic differentials in the prevalence of malnutrition therefore increased between 1975 and 1989. Trends in family income indicate extraordinary economic gains in the 1970s, some losses in the 1980s, and a modest net gain over the period 1975-89. The availability of sanitation, health, and education services, and the provision of preschool supplementary feeding programmes increased markedly in the 1970s and 1980s. Demographic trends were also positive, reducing the demand for services and programmes, increasing the economic efficiency of families, and concentrating the population in urban areas, where incomes, job opportunities, and social and material infrastructures are better. The observed nutritional improvement was therefore probably due to a moderate increase in family income associated with a substantial expansion in the provision of services and programmes, both of which were facilitated by favourable demographic trends. Also, the nutritional improvement was probably concentrated during the 1970s, while little, if any, occurred after 1980; prospects for the 1990s point to a stagnant situation. This is a reason for great concern particularly in the North and North-east regions of the country, where high rates of child malnutrition are still found.

Late onset autosomal dominant cerebellar ataxia. A family description and linkage analysis with the HLA system

A family suffering an autosomal dominant form of late onset hereditary cerebellar ataxia is described. Eight affected family members were personally studied, and data from another four were obtained through anamnesis. The mean age of onset was 37.1 +/- 5.4 years (27-47 years). The clinical picture consisted basically of a pure ataxic cerebellar syndrome. CT-scan disclosed diffuse cerebellar atrophy with relative sparing of the brainstem and no involvement of supratentorial structures. Neurophysiological studies (nerve conduction, VEP and BAEP) were normal. Twenty-six individuals were typed for HLA histocompatibility antigens. Lod scores were calculated with the computer program LINKMAP. Close linkage of the ataxia gene with the HLA system in this family could be excluded--0 = 0.02, z = (-2.17)--and the overall analysis of the lod scores suggest another chromosomal location than chromosome 6.

[Somatomedin, growth and nutritional status]

Serum somatomedins, or insulin-like growth factor(s) (IGF), originally characterized as primarily GH-dependent peptides, were found to also be dependent on insulin levels and nutritional status. Four properties characterize somatomedin peptides: their concentrations in serum are growth hormone dependent; they possess insulin actions in extraskeletal tissues; they promote the incorporation of sulfate into proteoglycans of cartilage; and they stimulate DNA synthesis and cell multiplication in certain types of cultured cells. Reduced somatomedin C levels are found in children with severe protein-energy malnutrition. Plasma concentration of growth hormone and cortisol are both elevated and there are low levels of insulin and somatomedin C. There is evidence that the ability of somatomedin C to stimulate cartilage is modulated by somatomedin inhibitor, factor that may act to limit growth in conditions of hormonal and/or nutritional deficiency. Dietary energy and protein appears to be particularly important for both generation of somatomedins and their action on growing cartilage. Measurement of somatomedins C concentration shows promise as a means for monitoring the response of malnourished patients and rats to nutrition repletion.

[Genetic analysis of lactose-fermenting Salmonella typhimurium isolated in Rio de Janeiro]

Lactose fermenting Salmonella typhimurium are endemic in São Paulo, but not in Rio de Janeiro Two isolations are described from the latter city. These Rio de Janeiro strains have a plasmid of 7.4 megadaltons. These plasmids were not auto-transferable, were thermostable and were not eliminated by acridine orange. One of these strains arose from a plasmid that had the lactose operon repressed, leading us to speculate about the evolution of the lactose fermenting character in Brazilian Salmonella.

Peculiar sequence organization of kinetoplast DNA minicircles from Trypanosoma cruzi

The sequences of two minicircles from the kinetoplast DNA of the CL strain and one of the Y strain of Trypanosoma cruzi are reported. These 1.4 kb molecules have a peculiar sequence organization, the most distinctive feature being the occurrence of a 120 bp sequence repeated four times, located at 0, 90, 180 and 270 degrees along each circle. We have termed these conserved regions in this species 'minirepeats'. Minirepeats have a 3-fold higher concentration of cytosine residues in comparison with the variable regions and contain the universal 12-mer motif GGGGTTGGTGTA present in all sequenced minicircles and which was shown to be involved in DNA replication. A consensus sequence of T. cruzi minirepeats was determined using the 20 minirepeats present in five known T. cruzi minicircle sequences. This consensus sequence contains regions which have been remarkably well preserved in strains which show great biological diversity. In addition a low level of intraminicircle sequence similarity was also observed within the variable region, but this similarity did not extend between strains. The abundance of conserved minirepeat sequences containing invariant restriction sites in T. cruzi cells may prove valuable for the development of new direct diagnostic methods for Chagas' disease based on DNA probe technology.