Showing papers by "Oswaldo Cruz Foundation published in 1991"

A cost-benefit analysis of Chagas disease control.

Abstract: Chagas disease transmission can be effectively interrupted by insecticidal control of its triatomine bug vectors We present here a simple model comparing the costs and benefits of such a programme, designed to eliminate domestic populations of Triatoma infestans throughout its known area of distribution over the seven southernmost countries of Latin America The model has been simplified to require only four financial estimates relating to the unit cost of housing spraying and benefits due to avoidance of premature death in the acute phase of the disease, avoidance of supportive treatment and care in the chronic phase of the disease, and avoidance of corrective digestive and cardiac surgery Except for these direct medical costs, all other potential benefits have been ignored Nevertheless, the model shows that the direct financial benefits of such a programme would far outweigh the costs, and the project would support a remarkably high internal rate of return under the least optimistic estimates

Extracellular matrix components of the mouse thymus microenvironment: ontogenetic studies and modulation by glucocorticoid hormones.

Abstract: The present investigation was an ontogenetic study on the distribution of extracellular matrix (ECM) components in the thymic microenvironment of C57BL/6 mice (comprising young and old adults and developing embryos) and NZB mice. In addition, we evaluated the in vivo and in vitro influence of hydrocortisone treatment on basement membrane protein production by a thymic epithelial cell line. In young normal animals, Type I collagen was restricted to the interstitial spaces of the capsule and septa, where Type IV collagen, fibronectin, and laminin could be detected in the basement membranes. In addition, fibronectin-containing fibers were seen within the medulla of the thymic lobules. The ECM distribution pattern in the developing embryos was distinct from that observed in adults, since a fine meshwork of basement membrane-containing proteins was clearly seen throughout the parenchyma. Moreover, aging normal and NZB mice exhibited a denser ECM pattern than young adult normal animals. Treatment with hydrocortisone, both in vivo and in vitro, resulted in enhancement of ECM expression, detected in mice as early as 2 hr post injection and lasting for several days. Considering that the fluctuations of ECM expression parallel important events in thymocyte differentiation, we discuss the possibility that the two phenomena may be associated.

Longitudinal study of acute respiratory diseases in Rio de Janeiro: occurrence of respiratory viruses during four consecutive years

Abstract: Investigamos, durante um periodo de 4 anos (1982 a 1985), a ocorrencia de virus em secrecoes de nasofaringe coletadas de criancas com menos de 5 anos de idade apresentando quadro clinico de infeccao respiratoria aguda (IRA), residentes na cidade do Rio de Janeiro. Foram encontrados todos os virus conhecidos como associados a IRA, com excessao do virus influenza C e parainfluenza 1, 2 e 4. Virus foram isolados mais frequentemente de criancas internadas em salas de emergencia e enfermarias que daquelas atendidas em ambulatorio. Este fato esta claramente relacionado com a alta inciencia do virus sincicial respiratorio (RSV) nos casos mais severos de IRA. Especimens positivos para RSV aparecem principalmente durante o outono, nos 4 anos consecutivos, indicando uma ocorrencia sazonal. As salas de emergencias sao a melhor fonte de dados para vigilância do RSV, onde um aumento no numero de casos positivos corresponde a um aumento no numero total de casos de IRA internados. Os adenovirus ocupam o segundo lugar entre os virus frequentemente isolados, sendo predominante os sorotipos 1, 2 e 7. Embora em menor numero os virus influenza e parainfluenza tipo 3 tambem sao encontrados. Virus influenza A foram isolados igualmente em criancas internadas em enfermarias, salas de emergencia e nos pacientes atendidos em ambulatorios, enquanto o virus influenza B e predominante neste ultimo grupo. O virus parainfluenza tipo 3 causou surtos anuais na populacao residente na favela durante o final do inverno ou primavera e foi isolado principalmente das criancas atendidas no ambulatorio. Herpesvirus, enterovirus e rinovirus foram encontrados com menor frequencia. Dos virus isolados somente o RSV e o parainfluenza tipo 3 mostraram uma incidencia sazonal bem definida.

Reversibility of cardiac fibrosis in mice chronically infected with Trypanosoma cruzi, under specific chemotherapy

Abstract: This investigation was performed to verify the effect of specific chemotherapy (Benznidazole or MK-346) on the inflammatory and fibrotic cardiac alterations in mice chronically infected with the strains 21 SF (Type II) and Colombian (Type III) of Trypanosoma cruzi. To obtain chronically infected mice, two groups of 100 Swiss mice each, were infected with either the 21 SF or the Colombian strain (2x 10 [raised to the power of] 4 and 5x 10 [raised to the power of] 4 blood forms respectively). The rate of morality in the acute phase was of 80% for both groups. Twenty surviving mice chronically infected with the 21 SF strain and 20 with the Colombian strain were then divided in treated and untreated groups. Excluding those that died during the course of treatment, 14 mice chronically infected with the 21 SF strain and 15 with the Colombian strain were evaluated in the present study. Chemotherapy was performed with Benznidazole (N-benzil-2-nitro-1-imidazolacetamide) in the dose of 100mg/k.b.w/day, for 60 days, or with the MK-436(3(1-methyl-5 nitroimidazol-2-yl) in two daily doses of 250 mg/k.b.w, for 20 days. Parasitological cure tests were performed (xenodiagnosis, haemoculture, subinovulation of the blood into newborn mice), and serological indirect immunofluorescence test. The treated and untreated mice as well as intact controls were killed at different periods after treatment and the heart were submitted to histopathological study with hematoxilineosin and picrosirius staining; ultrastructural study; collagen immunotyping, fibronectin and laminin identification by immunofluorescence tests. Results: the untreated controls either infected with 21 SF or Colombian strain, showed inflammatory and fibrotic alterations that were mild to moderate with the 21 SF strain and intense with the Colombian strain. Redpicrosirius staining showed bundles of collagen in the interstitial space and around cardiac fibers. Increased deposits of mitritial components and collagen fibers, macrophages and fibroblasts appeared at the ultra structural examination. Deposits of fibronectin, laminin, pro-III and IV collagens were seen, most intense in those infected with the Colombian strain. Treated nice, parasitologically cured, presented clear-cut regression of the inflammatory lesions and of the interstitial matrix thickening. Mice infected with the Colombian strain and treated with MK-436, was parasitologically cured in 5/6 cases and showed mild inflammatory infiltration and fibrosis. The mice treated with Benznidazole (Colombian strain) did not cure and showed moderate fibrosis and inflammation. Treatment of the nice infected with the 21 SF with Benznidazole determined parasitological cure of all animals, that showed mild inflammation and fibrosis of the myocardium. The cured mice of all groups and treated but uncured showed collagen degradation at electronmicroscopy and decrease of immunofluorescence pattern of the matrix.

Abordagem antropológica para avaliação de políticas sociais

Abstract: Apresenta-se uma abordgem antropologica relativa a avaliacao de programas de saude. Destaca-se o papel da antropologia, que sai de seu âmbito tradicional de pesquisa basica, para compor, de forma interdisciplinar com a medicina social um enfoque particular de avaliacao de politicas publicas e, mais estritamente, de servicos de saude. Coloca-se a antropologia dentro de um processo social mais abrangente, ao qual serve com seus instrumentos peculiares de apreensao da realidade. Baseando-se em pesquisa empirica de avaliacao da assistencia primaria a saude, numa favela do Rio de Janeiro, mostra que a abordagem qualitativa na avaliacao de programas de saude pode ser uma contribuicao importante que ajuda a superar as tendencias positivistas do processo avaliativo e a aprofundar visao mais totalizante do fenomeno saude-doenca.

Aspects of classification of Hemiptera hemocytes from six triatomine species

Abstract: The objective of this work was to characterize, and compare different morphological types of hemocytes of Rhodnius prolixus, Rhodnius, Rhodnius neglectus, Triatoma infestans, Panstrongylus megistus, and Dipetalogaster maximus. This information provides the basis for studying the cellular immune systems of these insects. Seven morphological hemocyte types wereidentified by phase-contrast microscopy: prohemocytes, plasmatocytes, granular cells, cytocytes, oenocytoids, adipohemocytes and giant cells. All seven types of hemocytes are not present in every species. For example, adipohemocytes and oenocytoids were not observed in P. megistus and P. infestans, and giant cells were rarely found in any of the species studied. The hemocytes of rhodnius and Dipetalogaster are more similar to each other than those from Triatoma and Panstrongylus which in turn closely resemble each other. Emphasis is placed on methodological problems arising in this work wicah are discussed in detail.

[An assessment of the nutritional status in a context of socioeconomic change: the Suruí Indians from the state of Rondônia, Brazil].

Abstract: This paper details the results of a nutritional assessment conducted with 147 Surui Amerindian children 0-8.9 years of age from the Aripuana Indian Park, Rondonia, Brazil. The data include anthropometry, hemoglobin concentration levels, and stool examinations. The Surui reservation is located in an area which experienced intensive government-oriented colonization and immigration over the past three decades. The group was contacted by the Brazilian Indian Foundation (FUNAI) in 1969 and, recently, became more involved in the regional market economy, which led to partial abandonment of traditional subsistence strategies. Compared to international reference curves (NCHS), the results indicate high levels of low height for age (46.3%), weight for age (31.9%) and weight for height (6.6%). Anemia (71.2%) and intestinal parasitism (over 75%) are also common. The authors argue that the precarious nutritional status of the Surui children reflects nutritional problems due to a reduction in the Surui food production system as well as inadequate sanitary conditions of the various villages.

Direct lysis of Trypanosoma cruzi: a novel effector mechanism of protection mediated by human anti-gal antibodies.

Abstract: Anti-gal antibodies directed against a carbohydrate epitope present in mouse laminin (galactosyl alpha 1-3 galactose) and detected in high levels in sera from patients in the acute phase of Chagas disease are responsible for the direct lysis (DL) of Trypanosoma cruzi blood forms independent of either the classic or alternative complement pathways. Furthermore, the lectins Euonymus europaeus (EE) specific for the carbohydrates gal alpha 1-3 gal present a similar lytic activity against T. cruzi at the same concentrations of purified anti-gal antibodies. The DL activity was tested with several other lectins but Concanavalin A (Con A) specific for alpha-D-mannose and alpha-D-glucose was the only one also presenting lytic activity. The lectins and anti-gal antibodies lytic activity can be inhibited by specific carbohydrates suggesting that this phenomenon is related to the capability of these lectins or anti-gal antibodies to bind to a crucial surface component of T. cruzi. Moreover, the infectivity of T. cruzi blood forms to mice was clearly inactivated by incubation with acute chagasic sera (ACS) but not by ACS absorbed by immunoaffinity chromatography with mouse laminin, a strong evidence that high levels of anti-gal antibodies participate in the decline of the parasitaemia from the acute to the chronic phase in Chagas disease.

Studies on the thymus in Chagas' disease. II. Thymocyte subset fluctuations in Trypanosoma cruzi-infected mice: relationship to stress.

Abstract: Changes in thymic T-cell subsets in mice acutely infected with Trypanosoma cruzi have been studied in both C3H/HeJ and C57BL/6 mice. The significant decrease in thymocyte number, observed in both mouse strains on day 14 post-infection correlated with a drastic decrease in CD4+CD8+ cell number, whereas the number of CD4−CD8−, CD4+CD8− and CD4−CD8+ cells remained essentially unchanged. The important increase in CD3hi cell frequency confirmed that resistant thymocytes during Chagas' disease development were mostly medullary thymocytes, whereas the thymic cortex was largely depleted, as previously observed on thymus sections. This involution of the thymus could have been due to the increase of circulating glucocorticoid levels observed after infection. However, similar cell modifications were found in infected adrenalectomized mice whose serum corticosterone levels were only slightly augmented. Thus, the thymic alterations appear not lo be linked to stress responses, al least those dependent on high levels of circulating glucocorticoids.

Depressed subjects unwittingly overreport poor social adjustment which they reappraise when recovered.

Abstract: Potential biases due to acute depressive symptomatology on raters' assessments of social maladjustment derived from patients' reports were assessed in 25 patients responding to pharmacotherapy during medium-term hospitalization. Patients were questioned on two separate occasions about their social maladjustment covering the exact same period (the 4 months preceding hospitalization): the first was during the acute illness phase, and the second a mean of 20.5 days later, when symptoms remitted. In the second report, composite scores for all fields as a whole showed significantly fewer reports of social impairment than did the first. Significant differences from the first to the second evaluation concerning both subjective distress and observable behavior were found in four and three, respectively, of the five "fields" of social adjustment. Although subjective distress was most modified by remission of acute symptoms, even supposedly objective, observable disturbances were significantly affected. These results indicate that acutely depressed patients overreport social maladjustment, which they then more accurately reappraise when symptoms remit. Patients are completely unaware of both the initial bias and of the reappraisal.

Trypanosoma rangeli (Tejera, 1920) isolated from a sylvatic rodent (Echimys dasythrix) in Santa Catarina Island, Santa Catarina State: first report of this trypanosome in southern Brazil.

Abstract: A trypanosome strain isolated from a sylvatic rodent (Echimys dasythrix) from Santa Catarina Island (Santa Catarina State, Brazil) was characterized by the following methods: experimental transmission and development in invertebrate hosts, morphometry, cross protection, complement sensitivity, lectin agglutination and isoenzyme profiles. Comparasions were made with standard Trypanosoma cruzi and T. rangeli strains. All methods except isoenzyne analysis led to the identification of the isolate as T. rangeli. The isoenzyme differences found could be explained on the basis of polymorphism. Therefore this is the first report of T. rangeli in southern Brazil, increasing the geographical distribution of this parasite.

Antimalarial chemotherapy with natural products and chemically defined molecules

Abstract: In the present work we have described the in vivo antimalarial actrivity of six different plants. Two of them (Verninia brasiliana and Eupatorium squalidum) were tested in a randomic approach among 273 crude extracts from plants; four (Acanhospermum australe, Esenbeckia febrifuga, Lisianthus specious and Tachia guianensis) were selected after screening 22 crude extracts from different medicinal and some of them showed antimalarial activity in vitro. Some aspects of recent research with natural products aiming to produce drugs are discussed.

Epidemiological and nosological aspects of Leishmania naiffi Lainson & Shaw, 1989.

Abstract: Leismania naiffi was isolated from 10 out of 64 armadillos (Dasypus novemcinctus) examined in Amazonas, Para and Rondonia States in the Brazilian Amazon Region The isolates were obtained in culture from samples of liver (3), spleen (3), lymph nodes (2), skin (1) and blood (1) from the infected animals Heavy infections with the same parasite were detected for the first time in Psychodopygus squamiventris, a common man-biting phlebotomine, in amazonas and Para A new case of cutaneous leishmaniasis caused by L naiffi is described from the Manaus area, making a total of three known cases of human infection by this parasite

Biological characterization of Trypanosoma cruzi strains from different zymodemes and schizodemes

Abstract: The development in C3H mice of thirteen strains of Trypanosoma cruzi belonging to different zymodemes and schizodemes was studied. Host mortality, virulence, histiotropism, parasitemia and polymorphism of the parasites were recorded. The strains were grouped into: a) high virulence--causing 100% mortality and characterized by predominance of very broad trypomastigotes in the bloodstream at the end of infection; b) medium virulence--causing no mortality and with a predominance of broad trypomastigotes; c) low virulence--causing no mortality with blood forms not described due to the very low parasitemia. During 18 months maintenance the parasitemia curves were kept constant for all strains except one. A direct correlation between either zymodeme or schizodeme and experimental biological properties of T. cruzi strains was not found. However, the parasitemia was subpatent and patent for strains from zymodeme C and the others respectively. Furthermore the high virulence seems to be related to one of two schizodemes found within zymodeme B strains. All strains presenting patent parasitemia independent of shizodeme and zymodeme showed a myotropism towards heart and skeletal muscle with variable inflammatory intensity. The present study confirmed the heterogeneity found by isoenzyme and k-DNA patterns among the strains of T. cruzi isolated from chagasic patients in Bambui, Minas Gerais State, Brasil.

A study of sandfly species (Diptera: Psychodidae: Phlebotominae) in a focus of cutaneous leishmaniasis in the municipality of Baturité, Ceará, Brazil

Abstract: In a study on putative vectors of cutaneous leishmaniasis in Baturite, Ceara State Brazil, six sandfly species were identified: Lutzomya longipalpis, L. wellcomei, L. peresi, L. whitmani, L. shannoni and L. migonei. In general L. whitmani and L. migonei were the predominant species. They were collected in periodomiciliary areas and were attracted by man and equines L. whitmani was the most anthropophilic species. Studies using animals as bait showed that blood-feeding occurs throughout the night. Previously L. whitmani had been found infected with a Leishmania species of the braziliensis complex and L. migoney was infected with peripylarian flagellates. In combination these findings suggest that they may be responsible for periodomestic transmission of cutaneous leishmaniasis.

Socioeconomic transition and physical growth of Tupí-Mondê Amerindian children of the Aripuanã Park, Brazilian Amazon.

Abstract: Anthropometric assessment of nutritional status is reported for three Tupi-Monde-speaking groups from Rondonia and Mato Grosso, Brazil. This region of the Amazon basin is experiencing rapid development through government-oriented colonization. The Gaviao, Surui, and Zoro had their first contacts with Brazilian national society at different times, and the nature and degree of their participation in regional markets varies. Height, weight, sitting height, subischial leg length, upper arm circumference, triceps skin-fold thickness, and upper arm muscle and fat areas are reported for children 0-10.9 years of age. Like other Amazonian Amerindians, Tupi-Monde children are short for their age but normal or above normal in weight for height with respect to the National Center for Health Statistics reference. Hence stunting levels are high (55.4%) and wasting levels are low (0.8%). There are also deficits in body composition parameters, especially in upper arm circumference and estimated muscle and fat areas. We interpret the results as evidence of suboptimal nutritional status, reflecting the interaction between poor diet and infectious and parasitic diseases. The Gaviao, with the longest period of contact, present the lowest level of stunting. This finding is attributed to the use of cash income from rubber tapping and nut gathering to purchase of food items and health care. Differences in height between the three groups are mostly due to leg length, instead of sitting height, reinforcing the idea that environmental conditions can alter body proportions.

Clinical and epidemiological aspects of abdominal angiostrongyliasis in Southern Brazil

Abstract: A maioria dos 16 casos de angiostrongiliase abdominal publicados no Brasil ate 1989, eram originarios dos Estados de Sao Paulo, Parana, Santa Catarina e Rio Grande do Sul (RS). Um estudo clinico e epidemiologico em 27 casos no RS revelou aspectos distintos do que e conhecido sobre a ocorrencia da doenca na Costa Rica: tanto adultos quanto criancas sao acometidos, provenientes de areas serranas do norte do Estado e ha uma aparente sazonalidade, nao relacionada as chuvas e sim aos meses mais quentes do ano. Alem de confirmar o quadro clinico-laboratorial descrito na literatura (dor abdominal, febre e eosinofilia), o estudo salienta a ocorrencia de episodios recorrentes de dor abdominal com remissao espontânea e de outras formas pouco sintomaticas, possivelmente as formas mais comuns de manifestacoes da doenca. Foi observada uma letalidade de 7,4%. Com o alerta aos medicos, especialmente da area endemica, e o uso de teste sorologico, espera-se um aumento do numero de diagnosticos de angiostrongiliase abdominal e consequente aprimoramento do conhecimento sobre esta zoonose no Brasil.

Screening of the antimalarial activity of plants of the Cucurbitaceae family

Abstract: Crude ethanolic extracts (CEEs) from two species of Cucurbitaceae, Cucurbita maxima and Momordica charantia (commonly called "abobora moranga" and melao de Sao Caetano", respectively) were assayed for antimalarial activity by the 4-d suppressive test. The CEE of dry C. maxima seeds showed strong antimalarial activity following oral administration (259 and 500 mg/kg), reducing by 50% the levels of parasistemia in Plasmodium berghey-infected mice. Treatment of normal animals with 500 mg/Kg of the extract three days before intravenous injection of P. berghei caused a significant 30% reduction in parasitemic levels. No effect was observed when the animals were treated with the CEE only on the day of inoculation. Oral administration of the CEE of dry M. charantia leaves adminstered orally was ineffective up to 500 mg/Kg in lowering the parasitemic levels of malarious mice.

Levels of the schistosome circulating anodic and cathodic antigens in serum of schistosomiasis patients from Brazil

Abstract: Serum levels of 2 schistosome circulating antigens, the circulating anodic antigen (CAA) and the circulating cathodic antigen (CCA), were determined in persons infected with Schistosoma mansoni in Brazil. Sensitive monoclonal antibody-based enzyme-linked immunosorbent assays were used to measure levels of the 2 antigens. The study group consisted of 38 individuals with intestinal schistosomiasis, and 20 persons with the hepatosplenic form of the disease. Age and intensity of infection were comparable for the 2 groups. CAA was detected in 65·5% of all patients' sera and CCA was found in the serum of 82·8% of all patients. CAA levels correlated well with the egg output, as determined by duplicate Kato-Katz smears; CCA was significantly positively correlated with egg output in patients with intestinal schistosomiasis only. Whereas no significant difference was found between CAA titre in patients with intestinal schistosomiasis and those with the hepatosplenic form, a significantly higher CCA titre was found in patients with hepatosplenomegaly compared to patients with intestinal schistosomiasis.

Effect of deltamethrin spraying on the sandfly populations in a focus of American cutaneous leismaniasis

Abstract: The effect of deltamethrin of the sandfly population in a focus of American Cutaneous Leishmaniasis in Viana, Espirito Santo State is desvribed. The phlebotomine population density was determined inside and outside houses during a one year period in a treated and untreated area. The results showed a significant reduction in the number of sandflies inside houses in the treated area compared with both the untreated area and the same area before sparying. Despite having a residual action for 12 months after spraying the insecticide was ineffective outside houses. It is concluded therefore that deltamethrin is an efficient insecticide for reducing the number of phlebotomine sandflies inside houses.

A multivariate analysis of socio-demographic factors, water contact patterns and Schistosoma mansoni infection in an endemic area in Brazil

Abstract: Associations between socio-demographic factors, water contact patterns and Schistosoma mansoni infection were investigated in 506 individuals (87% of inhabitants over 1 year of age) in an endemic area in Brazil (Divino), aiming at determining priorities for public health measures to prevent the infection. Those who eliminated S. mansoni eggs (n = 198) were compared to those without eggs in the stools (n = 308). The following explanatory variables were considered: age, sex, color, previous treatment with schistosomicide, place of birth, quality of the houses, water supply for the household, distance from houses to stream, and frequency and reasons for water contact. Factors found to be independently associated with the infection were age (10-19 and > 20 yrs old), and water contact for agricultural activities, fishing, and swimming or bathing (Adjusted relative odds = 5.0, 2.4, 3.2, 2.1 and 2.0, respectively). This suggests the need for public health measures to prevent the infection, emphasizing water contact for leisure and agricultural activities in this endemic area.

Identification of Vibrio cholerae by enzyme electrophoresis

Abstract: Zymovar analysis of 260 strains of Vibrio cholerae plus 3 reference strains of V mimicus , using 13 structural loci, led to the grouping of strains in 73 zymovars (strain or group of strains sharing the same alleles) Effective separation of strains, distinction of V cholerae strains from closely related V mimicus and the detection of 2 vibrio strains, including one with two O1 serovars, in supposedly pure collection cultures, illustrate the potential of zymovar analysis in the identification of V cholerae isolates Two El Tor strains from USA, one CT+ and the other CT−, shared the same zymovar 71, while 127 typical El Tor strains belonged to zymovar 14

Trichuris eggs in animal coprolites dated from 30,000 years ago.

Abstract: Trichuris eggs were found in Kerodon rupestris (Rodentia, Caviidae) coprolites collected in archaeological layers dated from 30,000 yr BP (before present) to 8,450 yr BP. Adult worms and eggs of this genus were not found in a search of living mammals of the region. Results indicate that K. rupestris was a host for an unknown Trichuris species not found in this rodent presently. Climate changes that occurred by 10,000 yr ago in the region could be the cause of its disappearance. The finding of parasites in archaeological material can show the antiquity of host-parasite relationships and parasite losses through time.

Oligonucleotide probes for the specific detection of the wild poliovirus types 1 and 3 endemic to Brazil.

Abstract: Synthetic oligodeoxynucleotide probes, 21–23 nucleotides in length, were prepared which specifically hybridize to the genomes of the wild type 1 and 3 polioviruses currently endemic to the northeastern region of Brazil. The probes are complementary to sequences near the 5’-terminus of the VPl gene that differ substantially among genetically distant polioviruses but are largely conserved among related isolates. The probes have been routinely used in the laboratory surveillance of poliomyelitis cases in Brazil, permitting direct, rapid identification of the indigenous wild polioviruses by dot-blot hybridization.