Showing papers by "Oswaldo Cruz Foundation published in 1982"
TL;DR: Findings demonstrate a dissociation between the antibodies mediating serological diagnosis and those directed against living bloodstream parasites, suggesting cure of Chagas's disease should be based not only on negative xenodiagnosis but also on the elimination of specific antibodies detectable by conventional serology and CML test.
Abstract: Clinical trials with compounds active in Chagas's disease have shown that after treatment parasitological diagnostic methods (xenodiagnosis) become repeatedly negative whereas conventional serology (immunofluorescence and complement fixation tests) persists steadily positive. Consequently, assessment of cure still remains controversial. This paper reports the influence of specific treatment on antibodies involved in the conventional serological diagnosis and on antibodies which bind to the living bloodstream forms and are related to host resistance. Antibodies lytic to Trypanosona cruzi bloodstream stages were detected, through a complementmediated lysis (CML) test, in: (a) 100% of 28 untreated patients; (b) 94% of a group of 21 treated patients in whom conventional serology. remained positive, including those with persistently negative xenodiagnosis; (c) 0% of 17 normal controls. In some patients treated with a nitrofuran derivative (nifurtimox) or with a 2-nitroimidazole derivative (benznidazol), CML test became gradually negative whereas conventional serology continued to be positive. Finally, in five patients treated with benznidazol, serological tests, CML and xenodiagnosis became regularly negative, strongly suggesting parasitolpgical cure. Those findings demonstrate a dissociation between the antibodies mediating serological diagnosis and those directed against living bloodstream parasites. Moreover, since in some patients both types of antibodies disappeared after treatment, the results suggest that cure of Chagas's disease should be based not only on negative xenodiagnosis but also on the elimination of specific antibodies detectable by conventional serology and CML test.
81 citations
TL;DR: Results suggest that endocytosis is the principal mechanism of internalization of T. cruzi by macrophages, and show also that epimastigote and trypomastigotes forms ofT.cruzi have a different rate of adhesion to the macrophage surface.
Abstract: Chicken macrophages, obtained by cultivation of blood monocytes, were infected with epimastigote and bloodstream trypomastigote forms ofTrypanosoma cruzi strain Y. The percentage of macrophages containing parasites within parasitophorous vacuoles and of flagellates attached to cell surfaces was determined. By incubation of the macrophages at 4°C or in the presence of cytochalasin B it was possible to dissociate the attachment from the internalization phases in the process of infection of macrophages. Both treatments had a marked effect on the internalization of epimastigote and trypomastigote forms. Cytochalasin B treatment and placement of the macrophages at 4° C before infection inhibited this process by about 99 and 96%, respectively. These results suggest that endocytosis is the principal mechanism of internalization ofT. cruzi by macrophages. They show also that epimastigote and trypomastigote forms ofT. cruzi have a different rate of adhesion to the macrophage surface.
65 citations
TL;DR: A review of lymnaeid samples collected by the author from 106 localities showed that one of them (from Ecuador) belonged to Lymnaea cousini Jousseaume, 1887, and all the others to either L. viatrix Orbigny, 1835 or l.
Abstract: A review of lymnaeid samples collected by the author from 106 localities in Mexico, Cuba, Jamaica, Haiti, Dominican Republic, Puerto Rico, Martinique, Saint Lucia, Guatemala, Costa Rica, Panama, Ecuador, Peru, Bolivia, Chile, Argentina, Uruguay andBrazil showed that one of them (from Ecuador) belonged to Lymnaea cousini Jousseaume, 1887, and all the others to either L. viatrix Orbigny, 1835 or l. columella Say, 1817. The ranges of L. viatrix and L. columella overlap in Middle America, and in northern and southern South America (Venezuela-Colombia-Ecuador and northeastern Argentina-Uruguay-southernmost Brazil, respectively). L. viatrix was the only species found in Peru west of the Andes and in Chile, and is supposed to have migrated eastward to Argentina via the Negro river basin. The range of L. columella in South America is discontinuous. The species has been recorded from Venezuela, Colombia and Ecuador and, east of the Andes, from latitudes 15o S (central-west Brazil) to 35o S (La Plata, Argentina). Such a gap may be attributed to either introduction from the northern into the southern area, or migration along the unsampled region on the eastern side of the Andes, or extinction in the now vacant area. No lymnaeids have been found so far in Brazil north of latitude 15o S and in the Guianas.
64 citations
TL;DR: A nitroimidazole-thiadiazole derivative displays a marked curative effect in mice experimentally infected with Trypanosoma cruzi, but cure rates were not observed when similar treatment schedules were used with standard and- T. cruzi drugs such as 5-nitrofuran and 2-nitrogenimidazoIe derivatives, including those already being used clinically.
Abstract: A nitroimidazole-thiadiazole derivative [(2-amino-5-(1-methyl-5-nitro-2-imidazolyl)-1,3,4- thiadiazole)] displays a marked curative effect in mice experimentally infected with Trypanosoma cruzi. When doses of 50 or 100 mg kg−1 were used for 20 consecutive days, parasitological cures (assessed by fresh blood examination, haemoculture, sub-inoculation, re-inoculation and indirect immunofluorescent test) were obtained in 100% of the animals. High curative levels were also observed with a single dose (500 mg kg−1) of this drug. Such cure rates were not observed when similar treatment schedules were used with standard and- T. cruzi drugs such as 5-nitrofuran and 2-nitroimidazoIe derivatives, including those already being used clinically.
63 citations
TL;DR: Examination of faeces and paired sera showed that this outbreak was caused by both rotavirus and a virulent strain of Shigella sonnei, which indicates a common source outbreak in a private school in the city of Rio de Janeiro.
Abstract: In May 1980 an extensive outbreak of gastroenteritis occurred in a private school in the city of Rio de Janeiro. Examination of faeces and paired sera showed that this outbreak was caused by both rotavirus and a virulent strain of Shigella sonnei. In the first 19 stool samples collected seven (37%) had rotavirus only, six (32%) had Sh. sonnei only, while four (21%) had both agents. Examination of the second and third stool collections revealed only the presence of Sh. sonnei. The 18 paired sera showed seroconversion for rotavirus in four cases (22%) and in seven cases (39%) for Sh. sonnei. The overall attack rate of the disease was approximately 75%, the nursery and kindergarten having higher attack rates. Students in all grades became sick at the same time, and the unimodal curve of the onset dates of symptoms indicates a common source outbreak. Evidence suggested a contaminated water supply.
55 citations
TL;DR: Results of one Bell and one Kato-Katz examination performed on each of 315 stool specimens from residents in an area in north-eastern Brazil endemic for schistosomiasis mansoni are compared to help clarify relationships between these methods and morbidity-infection relationships.
Abstract: We compare results of one Bell and one Kato-Katz examination performed on each of 315 stool specimens from residents in an area in north-eastern Brazil endemic for schistosomiasis mansoni. The prevalence of schistosome infection detected by the Bell technique was 76% and by the Kato-Katz technique was 63%. 81% (4454) of the infections missed by a Kato-Katz smear were light infections (one to 50 epg range by Bell examination). Over-all, 55% (4480) of stools in this egg count range by the Bell technique were negative on a single Kato-Katz smear. This implies that five Kato-Katz smears per stool would ensure a 95% probability (0·555 × 100) of detecting such light infections. However, a single Kato-Katz smear detected eggs in 97% (124128) of stools with a Bell count > 100 epg. For stools positive by both methods the egg counts per gram of stool were higher (p 400epg) by the Kato-Katz method than by the Bell method. The differing measurements of schistosome infection obtained with the Bell and Kato-Katz methods must be considered when comparing data on morbidity-infection relationships.
41 citations
TL;DR: These methods can be successfully used, in addition to classical criteria, for species identification of insect trypanosomatids, as verified by three different biochemical methods.
Abstract: In order to verify the applicability of biochemical methods for species identification of Trypanosomatidae, 13 species of monoxenic trypanosomatids plus the heteroxenous Trypanosoma cruzi were comparatively analyzed by three different biochemical methods. Insect trypanosomatids examined were: Crithidia acanthocephali, C. fasciculata (three varieties), C. luciliae luciliae, C. luciliae thermophila, C. deanei, C. oncopelti, Herpetomonas muscarum muscarum, H. megaseliae, H. samuelpessoai, H. mariadeanei, Leptomonas seymouri, L. collosoma, L. samueli, and Blastocrithidia culicis. Also included in the survey were aposymbiotic strains of C. deanei and C. oncopelti. Methods used were: electrophoretic profiling of endonuclease-generated fragments of k-DNA, esterase isoenzymes profiling, and polyacrylamide-gel electrophoresis (SDS-PAGE) of radioiodinated cell surface proteins. Interspecific but not intraspecific differences were detected by all three methods among the 13 monoxenic species examined. Thus, it is concluded that these methods can be successfully used, in addition to classical criteria, for species identification of insect trypanosomatids.
37 citations
TL;DR: A new species of South American lymnaeid snail, Lymnaea rupestris, is described, found only in its type-locality, Nova TeuTonia, a village in the municipality of Seara, state of Santa Catarina, Brazil.
Abstract: A new species of South American lymnaeid snail, Lymnaea rupestris, is described. So far it has been found only in its type-locality, Nova TeuTonia, a village in the municipality of Seara (27° 07' S, 52° 17' W), state of Santa Catarina, Brazil. It is distinguishable, by characteristics of the shell and internal organs, from the other two lymnaeid species known to occur in the area, Lymnaea columella and L. viatrix. Its shell has 4 markedly shouldered whorls, deep suture, ovoid or rounded aperture occupying about half the length of the shell, and reaches about 6 mm in length in adults; in columella and viatrix the shell has 4-5 rounded whorls, shallow suture, and reaches over 10 mm in adults; the aperture is ovoid, occupying about half the length of the shell in viatrix, about two thirds in columella. Anatomically it is readily separated from L. columella by the shape of the ureter, straight in rupestris, with a double flexure in columella. Comparison with L. viatrix shows the following main differences: distalmost portion of the oviduct with a low, caplike lateral swelling in rupestris, with a well-developed pouch in viatrix; uterus bent abruptly caudalward in rupestris, only slightly curved rightward in viatrix; basal half of the spermathecal duct hidden by the prostate in rupestris, wholly visible or nearly so in viatrix; spermiduct sinuous and uniformly wide in rupestris, straight and gradually narrowing in viatrix; prostate more than half as long and nearly as wide as the nidamental gland, and with a slit-like lumen in cross-section in rupestris, less than half as long as and much narrower than the nidamental gland, and with an inward fold in cross-section in viatrix; penial sheath about as long and as wide as the prepuce in rupesris, shorter and narrower than the prepuce in viatrix. An important ecological characteristic of L. rupestris is its habitat on wet rocks most often outside bodies of water, although in close proximity to them. Specimens were deposited in the following malacological collections: Instituto OswaldoCruz, Rio de Janeiro; Academy of Natural Sciences, Philadelphia; Museum of Zoology, University of Michigan; and British Museum (Natural History).
31 citations
TL;DR: The culture forms of L. pifanoi and the L. m.
Abstract: The culture forms of L. mexicana pifanoi (LRC L-90), L. mexicana mexicana (LRC L-94, M-379); L. braziliensis braziliensis (LRC L-77, L-1, M-2903, H-LSS) and L. mexicana amazonensis (H-JMMO, M-JOF, H-21, H-PLL,M-1696) were tested with the following lectins: Canavalia ensiformis, Ricinus communis-120, Axinella polypoides, Phaseolus vulgaris, Evonymus europaeus, lotus tetragonolobus, Dolichos biflorus, Aaptos papillata II, Laburnum alpinum, Ulex europaeus, Arachis hypogaea and Soja hispida. All examined strains of Leishmania were agglutinated by C. ensiformis, R. communis-120 and A. popypoides. No agglutination reactions were observed with P. vulgaris, D.biflorus, A. papillata II, E. europaeus and L. tetragonolobus. Only L. m. pifanoi and the L. m. amazonensis strains H-JMMO and MJOF showed agglutination reactions with S. hispida, U. europaeus, L. alpinum and A. hypogaea, while L. m. mexicana (LRC L-94; M-379) strains, L. b. braziliensis H. LSS, LRC L-77; L-1; M-2903 and the L. m. amazonensis strains, H-PLL, H-21, M-1696 showed no agglutination reactions with these four lectins.
23 citations
TL;DR: Foi visto nesta revisao que os parasitas do genero Leishmania induzem uma variedade de respostas complexas nos hospedeiros vertebrados, efetuadas e/ou moduladas pelo seu sistema imunologico.
Abstract: Parasites of the genus Leishmania induce a complex variety of responses in their mammalian hosts, effected and/or modulated by the immune system. The outcome of leishmanial infection of macrophages depends on factors particular to each host-parasite combination, involving not only intrinsic properties of the parasite, but also genetically determined characteristics of the host cell or of its interactions with immunocompetent cells. Following a review of evidence supporting these concepts, they are applied in describing the clinical and immunopathological spectrum of the disease as it occurs in man, with emphasis on the cutaneous and mucocutaneous leishmaniases of the Old and New World. Based on results obtained in experimental models of cutaneous leishmaniasis which reproduce features of healing and non-healing human disease, the author presents a schematic analysis of the evolution of the histopathological features of leishmanial lesions.
17 citations
TL;DR: Analysis of chromosomes of the Rhesus monkey has shown that karyotype standardization in the primates should not follow an anthropomorphic criterium because this may lead to inevitable incongruities.
TL;DR: The immunogenic and protective activity of an extract of S. mansoni cercariae, obtained by incubation of viable adult worms in buffered saline, was evaluated in rabbits and mice and resulted in the development of both humoral and cellular immune response.
Abstract: The immunogenic and protective activity of an extract of S mansoni, obtained by incubation of viable adult worms in buffered saline, was evaluated in rabbits and mice Animal immunization with this extract resulted in the development of both humoral and cellular immune response All immunized rabbits developed high levels (91 to 100%) of cytotoxic antibodies as determined by in vitro assays of cytotoxic activity of their sera against viable schistosomules Immunized animals challenged with S mansoni cercariae showed a lower parasite load than that of normal controls Protective activity was 886% and 540% in immunized rabbits and mice, respectively
TL;DR: Results show that enzyme variant profiles may contribute in elucidating parasite factors associated with such characteristics as virulence and tissue tropism in Leishmania, and suggest that adaptative modifications in enzymes may occur with changes in environment.
TL;DR: The fatty acid pattern of total lipids from T. cruzi is different from one of its growth medium because of the distribution of major fatty acids in phospholipid fraction and in neutral lipid fraction.
Abstract: 1. 1. The fatty acid pattern of total lipids from T. cruzi is different from one of its growth medium. 2. 2. The distribution of major fatty acids in phospholipid fraction was linoleic (50.4%), oleic (25.6%), stearic (10.1%) and palmitic (6.3%) and in neutral lipid fraction oleic and linoleic (about 29% each), palmitic (18.3%) and stearic (9.8%). 3. 3. In each of the individual phospholipids a particular fatty acid pattern was observed. 4. 4. For phosphatidylcholine: linoleic (55.7%), oleic (16.6%), stearic and palmitic (about 8% each) and polyunsaturated acids (4%). 5. 5. For phosphatidylethanolamine: linoleic (41.5%), oleic (27.6%), stearic (9.9%) and an unidentified fatty acid (9.2%). 6. 6. For phosphatidylinositol: stearic and linoleic (about 30% each) and oleic (22.1%).
TL;DR: An excess of hepatitis cases, in the research center of Petrobras located in the Fundaao Island, within the city of Rio de Janeiro, was notified during the second half of March 1980.
Abstract: An excess of hepatitis cases, in the research center of Petrobras located in the Fundaao Island, within the city of Rio de Janeiro, was notified during the second half of March 1980. In recent years this center has had an average of four cases per year, but between March 5th and April 25th, sixteen cases were reported. The cause and possible source of infection were investigated. A serologic diagnosis of hepatitis A was made by showing IgG serum antibodies against this virus in patients. No subclinical cases among a group of 60 healthy employees could be identified. A questionnaire was circulated to investigate a possible commom source of infection. Evaluation of the water supply system indicated that it had recently been contaminated. Information obtained from other medical services in the island failed to reveal that the episode was part of a larger outbreak.
TL;DR: Mitochondrial enzymes were detected cytochemically in all developmental stages of Trypanosoma cruzi maintained in tissue cultures at the light and electron microscope levels and showed no difference in the localization and intensity of the reaction.
TL;DR: A study was made of the male genitalia of five species which constitute the phyllosoma complex, showing some morphological informations to the modern taxonomy, emphasizing the relatioship between the species and the dificulty to the perfect understanding of the taxonomic status of each one.
Abstract: A study was made of the male genitalia of five species which constitute the phyllosoma complex: Triatoma phyllosoma (Burmeister, 1835), T. pallidipennis (Stal, 1872), T. longipennis Usinger, 1939, T. picturata Usinger, 1939 and T. mazzottii Usinger, 1941; all of them were found naturally infected by Trypanosoma cruzi, and, except T. picturata colonizing human houses. These species are very similar, not only by the external aspects but also by their geographical occurence in Mexico. The structures which constitute these genitalias were analysed comparatively with the intention to increase the knowledge of the mentioned species, showing some morphological informations to the modern taxonomy. There were identified four aedeagus structures: phallosoma, struts, endosoma and vesica processes; one on articulatory apparatus, the gonopore process; and other on pygophore, the pygophore process. These structures show small variations in size and shape, emphasizing the relatioship between the species and the dificulty to the perfect understanding of the taxonomic status of each one.
TL;DR: The technique for the first time in relation to Anopheles albitarsis and A. aquasalis, species of malaria vectors which are difficult to mate spontaneously in captivity, resulted in a high order of insemination.
Abstract: Many species of mosquitoes are unsuited to life in a laboratory because they fail to copulate in cages. This situation may be largely eliminated by the technique in current use for manually inducing inseminations as outlined. We have used this technique for the first time in relation to Anopheles albitarsis and A. aquasalis, species of malaria vectors which are difficult to mate spontaneously in captivity. The pre-mating age of the males and the temperature at which they are held affect the ability of male to transfer sperm. Mating males 8 to 14 days old with females at any age, resulted in a high order of insemination. Temperature of 25°C and humidity of 80% RH enhanced the degree of insemination.
TL;DR: The results indicate that strains belonging to different types (morphobiological and histopathological characters) also demonstrate important antigenic differences.
Abstract: Soluble extracts of Y, Sao Felipe and Colombian strains of Trypanosoma cruzi were analyzed against their homologous and heterologous antisera by crossed immunoelectrophoresis and crossed immunoelectrophoresis with intermediate gel. In the homologous system, the results showed 35 precipitin lines for Y strain (32 anodic, 3 cathodic), 24 precipitin lines for SaoFelipe strain and 22 for Colombian strain. No cathodic antigen was observed for these last two strains which were consequently considered particular to Y strain. Using crossed immunoelectrophoresis with intermediate gel, 5 antigens particular to Y were shown when reacted against anti-sao Felipe strain and 8 when reacted against anti-Colombian strain. Sao Felipe strains had one particular antigen when reacted against anti-colombian strain whereas none was observed when reacted against anti-Y strain. Finally Colombian strain did not show any particular antigen in reaction with anti-Y or anti-Sao Felipe strains. These results indicate that strains belonging to different types (morphobiological and histopathological characters) also demonstrate important antigenic differences.
TL;DR: A description of both male and female of a new species of phlebotomine sand fly caught in rock crevisses in Grao Mogol, State of Minas Gerais, Brazil, characterized by presenting the style with five spines and a branched paramere.
Abstract: Sao descritos o macho e a femea de uma nova especie de flebotomineo - Lutzomyia ramirezi sp. n. - coletada em fenda de rocha em Grao Mogol, Estado de Minas Gerais, Brasil. O macho e caracterizado por apresentar o dististilo com 5 espinhos e o paramero ramificado. A femea assemelha-se superficialmente as femeas do subgenero Lutzomyia s. str. porem, apresenta ascoides muito curtos e espinhos extremamente pequenos na parte posterior do faringe. A nova especie e incluida no grupo das especies "aberrantes ou isoladas" de acordo com Martins, Williams & Falcao, 1978. E tambem descrita a femea de Lutzomyia (Lutzomyia) alencari martins, Souza e Falcao, 1962, coletada na mesma regiao.
TL;DR: O presente trabalho mostra a histopatologia da infeccao pela Yersinia pestis, entre as diferentes especies de roedores silvestres e comensais (cricetideos, equimideos, murideos e cavideos) that ocorrem na zona endemica de peste do Nordeste do Brasil.
Abstract: O presente trabalho mostra a histopatologia da infeccao pela Yersinia pestis, entre as diferentes especies de roedores silvestres e comensais (cricetideos, equimideos, murideos e cavideos) que ocorrem na zona endemica de peste do Nordeste do Brasil. Estes roedores foram encontrados naturalmente infectados nos campos ou inoculados experimentalmente no laboratorio (vias percutânea, subcutânea ou picada de pulgas) com cepas locais e/ou estrangeiras de Yersiniapestis. Quase todos os animais, exceto alguns dos cavideos, desenvolveram a forma bubosepticemica da peste. Entre as lesoes encontradas, a necrose coagulativa multifocal do figado, a pneumonite intersticial aguda difusa e a atrofia linfoide do baco, podem, por sua constância, ser consideradas como os principais indicadores histologicos da infeccao pestosa, embora estas lesoes nao sejam exclusivas da peste. A diversidade e a intensidade das lesoes entre os Zygodontomys lasiurus pixuna, podem explicar a mortalidade elevada desta especie e a disseminacao da peste nos focos naturais do Nordeste brasileiro. Cricetideos e murideos mostraram alteracoes histopatologicas qualitativamente semelhantes. A resistencia dos cavideos a infeccao pestosa foi evidenciada pela sobrevida desses roedores a fase aguda da infeccao e pelo desenvolvimento de uma reacao histiocitaria interna, delimitando as areas abscedadas. e possivel que estas lesoes cronicas abriguem bacilos virulentos, que permitirao a reinfeccao periodica das pulgas e consequente reativacao do processo epizootico.
TL;DR: There was a serious lapse in the process of preparation of the gamma globulin in question, and it is recommended that the widespread assumption that this product is free of risks of transmitting hepatitis virus should be accepted with reservation.
Abstract: The authors studied an epidemic of hepatitis B occurring in an institution located in the Sao Cristovao section of the city of Rio de Janeiro, Brasil. Of a total of 35 cases detected, 30 ocurred in employees of the institution and 5 in family members of the employees. All the cases were considered as benign acute hepatitis; all but two were iteric. Clinically, a marked articular involvement was noted, with intense arthralgia and pronounced restriction of movement, which regressed completely as soon as jaundice became evident. The chronological distribution was typical of simultaneous infection from a single source. Epidemiological investigation indicated that the source was commercially prepared pooled human gamma globulin. Ironically, injections were given, as prophylaxis against hepatitis with disposable syringes. During two days of application, approximately 120 employees received gamma globulin injections, among whom 27 developed hepatitis with a mean incubation period of 116 days. Twenty six patients were tested for HBAg, with positive results in 12 (46.2%); 8 patients tested during the first two weeks of overdisease were all positive. The epidemic outbreak occurred in conditions, though not premeditated, approximating to those of an experimental study. In addition to the Sao Cristovao epidemic, the authors studied 8 cases seen at the hospital Service where they worked. These cases presented characteristics distinguishing them from the the type of hepatitis case commonly treated in that hospital. All these 8 patients were of elevated socioeconomic conditions, and all had a history of having received injections of gamma globulin from the same commercial source as that which gave rise to the Sao Cristovao epidemic. In these cases the mean incubation period was 106 days, and 5 of 6 patients tested were positive for HB Ag. Eleven lots of gamma globulin were tested in reference laboratories of the World Health Organization, six of these (53,5%) were positive for HB Ag. The authors conclude that there was a serious lapse in the process of preparation of the gamma globulin in question. It is recommended that the widespread assumption that this product is free of risks of transmitting hepatitis virus should be accepted with reservation.