Showing papers by "Universidade Federal de Minas Gerais published in 1989"
TL;DR: The Xenodiagnosis was performed according to Schenone's method used here as a reference technique and among the various groups of patients examined by both techniques the best results obtained were: 55.08% of positivity for hemocultures against 27.5% for xenodiagnotic.
Abstract: With the purpose of standardization of an hemoculture technique presenting a higher positive rate in the parasitological diagnosis of chronic Chagas' disease in patients with reactive serology (IFT, HA, CFT) the following schedule was used. Thirty ml of venous blood was collected with heparin and the plasma was separated by centrifugation (2.000 rpm/30'). The packed cells were washed with LIT medium or PBS which was then removed by centrifugation (2.000 rpm/15'). This material was sampled in 6 screw-tubes 18 x 200 with 6 ml of LIT medium and incubated at 28 degrees C. These incubated cultures at 28 degrees C were examined after 15, 30, 45 and 60 days. When the hemoculture was not immediately processed after blood collection, the plasma was removed and the sediment enriched with LIT medium and preserved at 4 degrees C. The Xenodiagnosis was performed according to Schenone's method used here as a reference technique. Among the various groups of patients examined by both techniques the best results obtained were: 55.08% of positivity for hemocultures against 27.5% for xenodiagnosis (X2 = 4.54, p = 0.05), with a tube positivity of 26.6%. Recommendation for screening trials of drug assays is the repetition of method on a same patient 2 or more times in different occasions, as used in xenodiagnosis.
155 citations
01 Jan 1989
TL;DR: The authors conclude that the scorpion venom acts at the peripheral nervous system, with release of chemical mediators (e.g., acetylcholine and catecholamines) and that part of the effects are reflex in nature and secondary to stimulation of vagai afferent fibers.
Abstract: The authors describe the pathophysiology of scorpion poisoning in animals, and the clinical findings and treatment in children. They conclude that the scorpion venom acts at the peripheral nervous system, with release of chemical mediators (e.g., acetylcholine and catecholamines) and that part of the effects are reflex in nature and secondary to stimulation of vagai afferent fibers. The treatment of 168 children severely poisoned by Tityus serrulatus scorpion venom in an Intensive Care Unit consisted of symptomatic measures, support of vital functions and neutralization of circulating venom. From 1972 to 1987 3860 adults and children were poisoned by scorpions, with a mortality rate of 0.28%.
126 citations
TL;DR: Callithrix kuhli uses dense vegetation for sleeping sites whereas L. chrysomelas uses tree holes, and uses the upper levels of the forest to forage in a more manipulative fashion at specific sites, such as epiphytic bromeliads, where they take generally larger prey.
121 citations
TL;DR: Pooled horse plasma containing antibodies against Crotalus durissus terrificus whole venom was digested with pepsin at an enzyme-substrate ratio of 8:1, pH 3.1, for 40 min and the F(ab')2M fragments purified by adding 8.7% caprylic acid (pH 5.0) revealed that the solution was free of IgG and of other plasma proteins, whereas that containing F( ab')2B was not.
72 citations
TL;DR: This study is based on interviews of people who use and market medicinal plants in the state of Minas Gerais in south east on Brazil and serves as a basis for the choice of species with pharmacological, parasitological and therapeutic potential.
Abstract: This study is based on interviews during 1983 -1988 of people who use and market medicinal plants in the state of Minas Gerais in south east on Brazil. The aim is to preserve popular local knowledge regarding the use of plants for medicinal purposes. The popular common name, the medical prescription and methods of preparation, the plant part use and the frequency with each plant was cited in the interview samples, are described for each species. The profession, age and social condition are given for each interviewee. A total of 84 cities were visited, resulting in the collection of 5000 dried herbarium specimes which have been classified into 311 species of 246 genera and 84 families, according to the most recent taxonomic nomencIature. This study permits constant revision and updating and serves as a basis for the choice of species with pharmacological, parasitological and therapeutic potential.
72 citations
TL;DR: It is postulated that primary forests are less complex habitats, when compared to secondary habitats in mid-stages of succession, and area size/species relationships should only be applied to conservation schemes if habitat structure is taken into account.
Abstract: This study investigated the effects of forest fragment size and habitat structure on species richness and diversity of Brazilian Atlantic forest small mammal communities. During the course of 17 months of live-trapping, a total of 57, 120 trap nights accumulated in six forest plots. There were three size categories: small (60-80 ha.), medium (860 ha) and large (35, 973 ha). At each site two forest sections were selected for small mammal sampling: one in primary and another in secondary succession stage. A total of 692 individuals belonging to 19 species were trapped 1, 366 times. Species diversity was measured using the Shannon-Wiener index H' and also a weighted version of this index that takes into account the number of individuals of each species trapped at the forests. The modified index was developed specifically for this study. The richest and most diverse forest for small mammals was the large secondary fragment, while the least diverse was the small mammal community of the small primary forest. Overall, species diversity is lower among primary forests, and also in forests of decreasing size. However, area sizel species relationship was only observed among secondary forests. It is postulated that primary forests are less complex habitats, when compared to secondary habitats in mid-stages of succession. Therefore, area size/species relationships should only be applied to conservation schemes if habitat structure is taken into account. By using multivariate regression methods in the investigation of the structural and size predictors of small mammal species diversity, it was possible to separate the effects of area size from those of habitat structure. Approximately half of the variance in small mammal species diversity between secondary forest fragments can be explained by area size, while habitat structure accounts for about 45% of the variation.
70 citations
TL;DR: This work proposes that in utero exposure of a fetus to some idiotypes expressed on placentally transferred antibodies induces anti-Id T lymphocyte sensitization, which is detected as a proliferative response by CBMC exposed to immunoaffinity-purified antibodies expressing the relevant idiotypes.
Abstract: Cord blood mononuclear cells (CBMC) of neonates born of mothers with Chagas' disease or schistosomiasis exhibited strong proliferative responses against idiotypes expressed on antibodies with specificity for Trypanosoma cruzi or Schistosoma mansoni antigens, respectively. These immunoaffinity-purified preparations were stimulatory if they were prepared from pools of patients' sera or from the mother's own serum, taken early during her pregnancy. These CBMC did not respond to normal immunoglobulin, and CBMC of neonates born of uninfected mothers did not respond to antibodies against either T. cruzi or S. mansoni, or normal immunoglobulin preparations. We propose that in utero exposure of a fetus to some idiotypes expressed on placentally transferred antibodies induces anti-Id T lymphocyte sensitization, which we detect as a proliferative response by CBMC exposed to immunoaffinity-purified antibodies expressing the relevant idiotypes. This is the first experimental evidence that children born of mothers with chronic infections undergo natural in utero idiotypic manipulations and are born possessing cellular anti-Id reactivity.
66 citations
TL;DR: 125I-iododerivatives of the insect toxin (AaH IT1) from Androctonus australis Hector and of one toxin (Ts VII) from Tityus serrulatus were purified by high performance liquid chromatography and used in binding experiments on a nerve cord synaptosomal fraction of cockroach.
46 citations
TL;DR: It was discussed the parasitological comprovation difficulties in chronic chagasic patients, the value of the simultaneous utilization of different triatomine species in xenodiagnosis and the hemoculture, in a favorable positive association to the sensistivity increase in the diagnosis' disease.
Abstract: Fifty nine chronic chagasic patients were simultaneously submitted to xenodiagnosis and hemoculture for Trypanosoma cruzi sampels isolations. The xenodiagnosis was done with 40 Panstrongylus megistus, Triatoma infestans and Dipetalogaster maximus nymphs, performing 120 triatomines. Groups of 10 insects per specie were dissecated and the intestinal content pooled and examine, after previous trituration and homogenization. The microscopically negative material was seed into LIT medium and examined after 20 days. Twenty nine patients were parasitologically proved, being 15 only by senoxiagnosis, 4 only by hemoculture and 10 by both methods. It was discussed the parasitological comprovation difficulties in chronic chagastic patients, the value of the simultaneous utilization of different triatomine species in xenodiagnosis and the hemoculture, in a favorable positive association to the sensistivity increase in the diagnosis' disease. The 49,2% of posistivity obtained in this group, visualize approaches like clinic-therapeutic assay and or epidemiological (case-control) with the purpose to investigate a possible association with T. cruzi sampels and different clinic forms in Chagas' disease.
44 citations
TL;DR: The data suggest the involvement of circulating factors in the sympathetic denervation phenomena but indicate that local inflammatory process is, at least, an aggravating factor.
Abstract: Tissue parasitism, inflammatory process (histologic methods) and sympathetic denervation (glyoxylic acid-induced histofluorescence for demonstration of catecholamines) were studied in the heart (atrium and verntricle) and the submandibular gland of rats infected with the Y strain of Trypanosoma cruzi. In the heart paralleling intense parasitism and inflammatory process, the sympathetic denervation started at day 6 of infection and at the end of the acute phase (day 20) practically no varicose nerve terminals were found in both myocardium and vessels. In the submandibular gland, in spite of the rarity of anastigote pseudocysts and the scarcity of inflammatory foci, slight to moderate (days 13-15 of infection) or moderate to severe denervation (day 20) was found. At day 120 of infection both organs exhibited normal pattern of sympathetic innervation and only the heart showed some inflammatory foci and rare psudocysts (ventricle). Our data suggest the involvement of circulating factors in the sympathetic denervation phenomena but indicate that local inflammatory process is, at least, an aggravating factor.
42 citations
TL;DR: Kinetic properties of the enzyme were determined for representative synthetic chromogenic substrates and inhibitors and revealed a single broad band with apparent M r of 41–47 kDa.
Journal Article•
TL;DR: A case of Schilder's myelinoclastic diffuse sclerosis in a 14-year-old girl with sudden bilateral visual loss is reported, with almost complete visual recovery and shrinkage of the lesions.
Abstract: We report here a case of Schilder's myelinoclastic diffuse sclerosis in a 14-year-old girl with sudden bilateral visual loss. Computed tomographic scan showed two large symmetrical lesions in the occipital lobes and a smaller hypodense area in the frontal lobe. Cerebrospinal fluid examination revealed increased immunoglobulin G fraction with the presence of oligoclonal bands. Ultrastructural study of a biopsy specimen disclosed a demyelinating disorder with no cytoplasmic inclusions. Steroid treatment was followed by a dramatic response, with almost complete visual recovery and shrinkage of the lesions.
TL;DR: In this paper, the authors proposed a method for the identification and classification of animals in the Basic Institut of Medical and Agricultural Biology Universidade Estadual Paulista, Botucatu, Brazil.
Abstract: Department of Zoology, Basic Institut of Medical and Agricultural Biology Universidade Estadual Paulista, Botucatu, Sao Paulo
Journal Article•
TL;DR: The results demonstrate that resident microbes protect mice from the pathogenic effect of S. typhimurium infection.
Abstract: The present study investigates the lethality of intragastric Salmonella typhimurium infection of germfree (GF) and conventional (CV, not germfree) mice. The introduction of only 10 viable S. typhimurium into the gastrointestinal tract of GF mice resulted in death of all animals within 8 days of inoculation. In contrast, the 50% lethal dose for CV mice was 4.7 x 10(3) viable organisms. The results demonstrate that resident microbes protect mice from the pathogenic effect of S. typhimurium infection.
TL;DR: In this article, a block renormalization group transformation (RGT) for lattice and continuum Euclidean Fermions in d dimensions is developed using Fermionic integrals with exponential and δ-function weight functions.
Abstract: Block renormalization group transformations (RGT) for lattice and continuum Euclidean Fermions in d dimensions are developed using Fermionic integrals with exponential and “δ-function” weight functions. For the free field the sequence of actionsDk generated by the RGT from D, the Dirac operator, are shown to have exponential decay; uniform ink, after rescaling to the unit lattice. It is shown that the two-point functionD−1 admits a simple telescopic sum decomposition into fluctuation two-point functions which for the exponential weight RGT have exponential decay. Contrary to RG intuition the sequence of rescaled actions corresponding to the “δ-function” RGT do not have uniform exponential decay and we give examples of initial actions in one dimension where this phenomena occurs for the exponenential weight RGT also.
Journal Article•
TL;DR: The hemodynamic changes probably played an important role in the pathogenesis of the functional and histopathologic renal changes developed by the animals after venom injection.
Abstract: 1. Ninety-eight adult female rats were injected with 14 micrograms/g B. jararaca venom intraperitoneally to determine functional and histopathological renal changes. 2. Glomerular filtration rate, renal plasma flow, filtration fraction, osmolar clearance, water transportation in collecting ducts, urinary sodium excretion, fractional sodium excretion, albuminuria, urinalysis, plasma creatinine, urinary output and mean arterial pressure were studied before and 24 and 48 h after venom administration. Light microscope examination of the kidneys was carried out in another group of rats before and 2, 5 and 24 h after venom administration. 3. Treated animals developed acute renal failure characterized by a decrease in glomerular filtration rate, osmolar clearance, and fractional and urinary sodium excretion, and by an increase in plasma creatinine. There was also a decrease in renal plasma flow and mean arterial pressure. Histopathological examination of the kidneys indicated mild proliferation of the mesangial matrix and degenerative changes of the tubules characterized by loss of brush border and cytoplasmic vacuolation. 4. The hemodynamic changes probably played an important role in the pathogenesis of the functional and histopathologic renal changes developed by the animals after venom injection.
TL;DR: In this article, an analytical proof is given that the motion of n point vortices in the plane is non-integrable forn>3, where n is the number of points in a plane.
Abstract: An analytical proof is given that the motion ofn point vortices in the plane is non-integrable forn>3. The basic geometric configuration, which models a situation often found experimentally, consists of two opposite strong vortices and two advected weak vortices. We use “Melnikov's method,” as presented by Holmes and Marsden [Commun. Math. Phys.82, 523–544 (1982)]. The Melnikov integral is explicitly evaluated, by residues, in the limiting situation where one of the weak vortices is very close to one of the primaries.
TL;DR: In this paper, the authors demonstrated the existence of a broad co-accomodation of Amblyomma pseudoconcolor on Endentata of the family Dasypodidae.
Abstract: We received for examination a small colection of ticks captured in the National Park of the Serra da Canastra (MG), between 1979 and 1980. The authors demonstrated the existence of a broad co-accomodation of Amblyomma pseudoconcolor on Endentata of the family Dasypodidae, being Dasypodini the tribe more adjusted to this infestation. In conformity to the Figs 1 and 2, Dasypodini are probably the real hosts of A. pseudoconcolor and also the oldest hosts. For the first time, A. pseudoconcolor is also recorded on Cabassous tatouay, C. unicintus, Priodontes maximus and Euphractus sexcinctus. Also for the first time A. pseudoconcolor and Amblyomma calcaratum were recorded in the State of Minas Gerais. The extoparasites are deposited in the "Departamento de Parasitologia da Universidade Federal de Minas Gerais, Brasil".
TL;DR: Results indicated that scores tended to increase with age and that sex differences were not significant, and jumping jacks were found to be the most reliable and the easiest of the three tasks.
Abstract: The purpose of this study was to collect normative data on and to assess the clinical usefulness of scales designed to measure the quality of children's ability to perform three bilateral motor coordination tasks: jumping jacks, symmetrical stride jumps, and reciprocal stride jumps. One hundred children, aged 5 to 9 years, were tested according to the scales developed for this study. Results indicated that scores tended to increase with age and that sex differences were not significant. Jumping jacks were found to be the most reliable and the easiest of the three tasks. Reciprocal stride jumps were the most difficult. Quality of performance was assessed, and the number of jumps in a 10-sec trial was recorded for each age. The data from this study may be useful in comparing the performance of children with motor deficits to the performance of normal children of the same age.
TL;DR: The egg of Sarcodexia lambens (Diptera: Sarcophagidae) is described on the basis of scanning electron microscopy.
Abstract: The egg of Sarcodexia lambens (Diptera: Sarcophagidae) is described on the basis of scanning electron microscopy.
TL;DR: It is found that the leading correction to the sine-Gordon expression for the soliton density and the quantum soliton energy comes from the out-of-plane magnon mode, not present in the pure SG model.
Abstract: We study the quantum-statistical mechanics, at low temperatures, of a one-dimensional antiferromagnetic Heisenberg model with two anisotropies. In the weak-coupling limit we determine the temperature dependences of the soliton energy and the soliton density. We have found that the leading correction to the sine-Gordon (SG) expression for the soliton density and the quantum soliton energy comes from the out-of-plane magnon mode, not present in the pure SG model. We also show that when an external magnetic field is applied, the chain supports a new type of kink, where the sublattices rotate in opposite directions.
TL;DR: 'Blood in the stool' and a 'palpable and hardened liver' showed the highest positive predictive value; their presence, even in relatively low prevalence areas may be used by the health field workers as an indication of the existence of more advanced clinical forms of the disease.
Abstract: The signs and symptoms classically associated with Schistosoma mansoni infection were analysed in relation to their sensitivity, specificity and positive predictive value in identifying S. mansoni patients as well as more severe forms of the disease under field conditions. Data was collected in a survey conducted in a small urban area in the south east of Brazil (14.3% infection in the studied sample with a geometrical mean excretion of 95.5 S. mansoni eggs/gram of faeces). 'Blood in the stool' and a 'palpable and hardened liver' showed the highest positive predictive value; their presence, even in relatively low prevalence areas may be used by the health field workers as an indication of the existence of more advanced clinical forms of the disease.
TL;DR: Two naturally infected dogs and two other dogs infected with 1 x 106 promastigotes of MHO BR 70 BH46 Leishinania were maintained and autopsied after 10 months and two years, finding main findings concerning the kidney.
Abstract: Two naturally infected dogs (male and fema lei from Teofilo Otoni (MG Brazili were maintained for 18 months in our laboratory. Two other dogs, two months old males were infected with 1 x 106 promastigotes of MHO BR 70 BH46 Leishinania (Leishmanial chagasi strain, endo venous route, and autopsied after 10 months and two years. The main findings concerning the kidney were: (1) focal or diffuse mesangial glomerulo nephritis with proliferative and enlargement of mesangial cells; (2) increase in thickness of basement membrane with electron dense deposits: (3) chronic interstitial nephritis with intense exudation of plasmocytes: (4) cloud swelling of renal tubules. The authors discuss the probable pathogenetic mechanisms.
TL;DR: The exploitation of army ant swarm raids by marmoset monkeys of the genus Callithrix (family Callitrichidae) in four widely separated localities in Brazil is reported on.
Abstract: The disturbance of the forest litter arthropod fauna caused by the swarm raids of the New World army ants, Eciton burchelli (Westwood, 1842) and Labidus praedator (F. Smith, 1858) (subfamily Ecitoninae, tribe Ecitonini) is exploited for foraging by a large number of bird species, principally of the families Cuculidae, Dendrocolaptidae, Thraupidae and Formicariidae. Willis & Oniki (1978) review this phenomenon and also document that toads, Bufo marinus (L., 1788), teid lizards (Ameiva and Kentropyx) and iguanids (Anolis frenatus (Cope, 1899) may also associate with army ant swarms for this reason. Here we report on the exploitation of army ant swarm raids by marmoset monkeys of the genus Callithrix (family Callitrichidae) in four widely separated localities in Brazil. This association was first observed in 1978 during a year-long study of C. humeralifer (Geoffroy, 1812) in tropical Amazonian rain forest at Aripuana in the State of Mato Grosso (100 10' S, 590 27' W) (Rylands 1981). When encountering swarms of either E. burchelli or L. praedator, the marmosets would take up positions at the front of the swarm on perches up to one metre above the ground and spend as much as two to three hours picking off disturbed insects or those which had already been captured by the ants. Principal foods at this time were crickets, grasshoppers, cockroaches and spiders. When taking prey already captured by the ants they would agitatedly manipulate and shake the prey till the ants were removed before eating it. On occasion they were
TL;DR: A synergistic effect between schistosomicides and steroids in the treatment of the early stages of Schistosoma mansoni infection in the mouse is reported, showing apparent inhibition of fecundity of S. mansoni by combining these drugs has clear implications for Treatment of the Katayama syndrome.
Abstract: The best therapeutic approach to acute schistosomiasis (Katayama fever) is still unsettled. In this paper we report a synergistic effect between schistosomicides and steroids in the treatment of the early stages of Schistosoma mansoni infection in the mouse. CBA mice infected with 150 S. mansoni cercariae were treated with oxamniquine or praziquantel and dexamethasone or prednisolone. The rate of parasite egg excretion by treated mice and appropriate controls was monitored, and the mice were perfused 43 d after infection for estimation of worm burdens and tissue egg densities. Mice treated with schistosomicides alone or with schistosomicides plus steroids had worm burdens of similar size. Significant reductions in egg counts were, however, recorded in faeces, and in the intestines and livers (with consequent reduction in liver pathology), of mice treated with schistosomicide and steroid, when compared to mice treated with schistosomicide alone or steroid alone. The apparent inhibition of fecundity of S. mansoni by combining these drugs has clear implications for treatment of the Katayama syndrome.
TL;DR: In this paper, the two-and-three-dimensional Ashkin-Teller model is studied within two renormalization group treatments and the complete flow diagram is obtained for this two-parameter Hamiltonian and the results for the critical couplings and critical exponents are compared to the exact ones when avaible.
Abstract: The two-and-three-dimensional Ashkin-Teller model is studied within two renormalization group treatments. The complete flow diagram is obtained for this two-parameter Hamiltonian and the results for the critical couplings and critical exponents are compared to the exact ones when avaible.
Journal Article•
TL;DR: It is concluded that the splenogastric vessels are sufficient for the maintenance of spleen irrigation and drainage and the length of the spleen remnants does not change for at least 2 months after surgery.
Abstract: 1. Postsplenectomy complications have stimulated surgeons to opt for partial splenectomy as a more desirable technique for several diseases and in some cases for trauma to the spleen. 2. We studied spleen viability in 15 dogs submitted to subtotal splenectomy while maintaining the upper pole and upper splenogastric vessels. Macro- and microscopic histological studies as well as Tc99m-labeled heat-damaged erythrocyte scintigraphic analysis of splenic blood irrigation were carried out. 3. We conclude that: a) the splenogastric vessels are sufficient for the maintenance of spleen irrigation and drainage; b) the spleen remnants develop increased cellularity of the splenic cords and lymphoid folliculi; c) the length of the spleen remnants does not change for at least 2 months after surgery.
TL;DR: In this article, a new DNA amplification was described from an isolate of the lizard parasite Leishmania tarentolae, which was named the T amplification (for Tarentolaae/Trager).
Abstract: A new DNA amplification is described from an isolate of the lizard parasite Leishmania tarentolae. This DNA is present in up to 50 copies in the Trager line of this species and present but not amplified in all other lines tested. This amplification has been named the T amplification (for Tarentolae/Trager). Restriction enzyme digestion and electrophoresis of total DNA reveal amplified fragments totalling 19 kb following staining with ethidium bromide, a finding confirmed by the use of specific hybridization probes. Much of the amplified T DNA occurs as extra-chromosomal circular molecules. No cross-hybridization was observed between the T region and other amplified DNA of Leishmania, or the maxicircle of L. tarentolae, nor was resistance to methotrexate, chloroquine or primaquine detected in the T-amplified line. Combined with our previous results showing H region amplification in 2 other unselected lab stocks, these data demonstrate the prevalence of apparently spontaneous gene amplifications in L. tarentolae.
TL;DR: DDT levels were consistently lower in women who had nursed 3 or more children, than those with 1 or 2, and HCH content was higher in younger women than older, and in houses that had been sprayed, especially in rural zones, where spraying programs are run by the public health authorities.
Abstract: The use of organochlorine insecticides has been common since the forties. But this has become a serious problem of public health, due to the fact that insecticides accumulate in tissues owing to their fat-soluble character, their persistence in the environment and their accumulation in the food-chain. The continuous development of gas chromatographic techniques allowed the detection of ppb levels of these insecticide residues. Studies with laboratory animals have been useful to establish the toxicity of these compounds. Human milk can be used as an evaluation index of environmental contamination by these insecticides, although the main objective of its analysis is to determine the amounts ingested by children. When evaluating the levels of organochlorine insecticides in human milk it is useful to establish where the mothers live. Theoretically, mothers who live in a rural area have much more contact with these insecticides, because they work directly in agriculture. Therefore, the risk of exposure by their nursing children will be even greater. In Brazil, farmers do not have enough knowledge to measure the risks brought about by their indiscriminate use. In addition, government programs for the control of rural endemic diseases still make use of DDT and HCH on a large scale.