158 resultados para biological aspects
Resumo:
Hamster inoculated intraperitoneally with 1 x 10(7) parasites of L. donovani and L. major-like of the New World were studied in groups of 15, 30, 60 and 90 days of infection. The parasite load and density showed progressive increase with the evolution of the infection and was higher in the L. donovani groups than in the L. major-like groups. The L. major-like groups showed parasite density higher in the spleen than in the liver and was similar in both organs in L. donovani groups. The histopathology showed a diffuse marked hyperplasia and hypertrophy of the reticuloendothelial system with high parasitism in the L. donovani groups while there was focal involvement of these organs in L. major-like groups, forming nodules of macrophages that were scantly parasitised. The biological behaviour could be useful in the preliminary studies of Leishmania strain in regional laboratories and understanding the histopathology of lesions caused by different leishmania species.
Resumo:
A ten year (1976-1986) review study of cases of Actinomycetoma in Venezuela was made through personal interview and clinical examinations, analysis of medical records of patients with actinomycetoma, histological studies of biopsy samples, as well as microbiological studies of isolates strain, also through out personal interviews with researchers and dermatologists who were sources of information on mycetoma cases. A total of 47 cases were recorded. As etiologic agent Actinomadura madurae was found in 20 cases - (42.5%), Nocardia brasiliensis in 13 cases (27.6%), Nocardia spp 7 cases (14.8%), Streptomyces somaliensis in 4 cases (8.5%), N. asteroides in 2 cases (4.2%) and N. otitidis caviarum, (N. caviae) in 1 case (2.1%). Most of the reported cases involved individuals living and working in rural areas, mostly males who outnumber females 4:1. The patients were 18 to 80 years old. A. madurae was reported as the most frequent etiologic agent. Most of the clinical cases were seen when the disease was well established. Twenty four of the forty seven cases reported were observed in Lara State, which represents a 51.0% of all the cases studied.
Resumo:
This report shows the phlebotomine vectorial role in the endemic cutaneous leishmaniasis situated in the middle and north-eastern region of the São Paulo, Brazil. Analysis of information encloses a sandfly man-biting fauna of four different patches of residual forest. So, using the human-bait and Shannon trap for a period of one year we have caught 16,869 sandflies. The predominance of Lutzomyia intermedia (85,6%) was clear. Moreover, the low density of Lutzomyia whitmani and Lutzomyia pessoai and their epidemiological implications at present and in the past are discussed. Information about the daily activity of some species is given and we emphasize for the first time, the diurnal activity of Lutzomyia firmatoi in the São Paulo State.
Resumo:
Hepatobiliary alterations found in an autopsy case of massive Biliary Ascariasis, are reported on histological grounds. Severe cholangitis was the main finding, but other changes were also detected, such as pyloric and intestinal metaplasia, hyperplasia of the epithelial lining, with intraductal papillomas and adenomatous proliferation. Remnants of the worm were observed tightly adhered to the epithelium, forming microscopic intrahepatic calculi. Mucopolysaccharides, especially acid, showed to be strongly positive on the luminal border, and in proliferated glands around the ducts. The authors discuss the similarity between such findings and Oriental Cholangiohepatitis, and suggest that inflammation and the presence of the parasitic remnants are responsible for the hyperplastic and metaplastic changes, similarly with what occurs in chlonorchiasis, fascioliasis and schistosomiasis.
Resumo:
Most of the cases of abdominal angiostrongyliasis in Brazil were reported from the southern States of São Paulo, Paraná, Santa Catarina and Rio Grande do Sul (RS). A study in 27 cases from RS revealed a distinct local epidemiology. Peasants were usually affected, either adults or children, from the mountainous areas in the north of the Suite. There was a seasonal increase in the number of cases, from late spring to autumn, that does not coincide with the rainy season. Besides the most common clinical features of abdominal pain, fever and cosinophilia in the leucogram, painful relapsing episodes were detected in some patients. The abdominal pain could be either localized or diffuse during the rapid evolution to a surgical abdominal condition, with a letality of 7.4%. The use of a serological test and the greater awareness of physicians working in endemic areas is expected to improve the recognition of uncomplicated and benign courses of the disease. This study confirms the known clinical manifestations of abdominal angiostrongyliasis and demonstrates the diversity of its epidemiology.
Resumo:
In the São Paulo State, Brazil, where the Biomphalaria tenagophila is the intermediate host, the Ribeira Valley is an important endemic schistosomiasis mansoni area. During last eleven years there has been intense control measures focusing on schistosomiasis. The efforts have been concentrated in the municipalities of Pedro de Toledo and Itariri. We determined the susceptibility of B. tenagophila to sympatric strain of S. mansoni, both recently isolated from Itariri field. In 1988, this strain was isolated and maintained in the experimental model: Swiss mice - sympatric B. tenagophila. The second generation of the worm was evaluated. The snail were divided in the three groups of 60 snails each. One group was exposed to 1 miracidium and other to 10. The third group was the control. The mortality and the shedding of cercariae were checked during 78 days. After that, the positive snails were observed until they ceased to shed cercariae. The exposed molluscs showed mortality rates of 23% and 31% and infection indexes were of 8% and 60% to 1 and 10 miracidia respectively. The mortality was of 22% in the control group. The periods of shedding cercariae in the two groups were 82 and 104 days. We can conclude that B. tenagophila is an effective intermediate host to the sympatric strain of S. mansoni sympatric strain
Resumo:
Fasciola hepatica somatic antigen, its partially purified fractions and excretion-secretion products were investigated as to serological, electrophoretic and biological properties. In a Sephadex G-100 column (SG-100), Fasciola hepatica total antigen (FhTA) gave 5 fractions, and SDS-PAGE analysis showed they were glycoproteins ranging from 14 to 94 kDa molecular weight (MW). When these fractions were analyzed by enzyme linked immunotransfer blot (EITB) and immunodiffusion in gel (ID) with serum from immunized rats with FhTA, the presence of different antigenic components was revealed. In the SDS-PAGE of excretor-secretor antigen (ESA), it was possible to observe peptides from 12 to 22 kDa, which were also present in FhTA. When the FhTA, its fractions and the ESA were analyzed by EITB with the immune rat serum (IRS), it was observed that only some fractions of the SG-100 shared antigens with the FhTA and ESA. Moreover, DTH and ITH responses were studied in FhTA immunized rats challenged with these different antigen components, revealing that the protein/carbohydrate ratio is important for inducing DTH response. The ESA was the most active component in the DTH and ITH response.
Resumo:
Laboratorial studies were carried out on 3178 patients with signs and symptoms suggestive of dengue infection from April 1986 to December 1987 in the State of Rio de Janeiro, Brazil. The epidemic had two peaks following the first virus isolation and affected the inhabitants of 17 counties. Both sex and all age groups were affected. Dengue virus type 1 was isolated from 1039 sera and the number of confirmed cases was increased to 1874 (59%) by MAC-ELISA. Isolation rate confirmed cases reached 80% in the specimens obtained until the 4th day after the onset of disease and viraemia ranged from 10 3.0 to 10(8.5) TCID50/ml.
Resumo:
Scorpion stings in Brazil are important not only because of their incidence but also for their potential ability to induce severe, and often fatal, clinical situations, especially among children. In this report we present the clinical and laboratory data of 4 patients victims of scorpion stings by T. serrulatus, who developed heart failure and pulmonary edema, with 3 of them dying within 24 hours of the sting. Anatomopathologic study of these patients revealed diffuse areas of myocardiocytolysis in addition to pulmonary edema. The surviving child presented enzymatic, electrocardiographic and echocardiographic changes compatible with severe cardiac involvement, which were reversed within 5 days. These findings reinforce the need for continuous monitoring of patients with severe scorpion envenoming during the hours immediately following the sting.
Resumo:
Histopathological and ultrastructural studies of 23 patients who died with clinical diagnosis of measles were carried out. In 12 cases viral nucleocapsids were searched by electron microscopy and detected in 100% of the cases in the lungs and in 50% of the cases in the central nervous system. They were mostly intranuclear. Histopathological changes associated to neurological alterations and the detection of virion are discussed in relation to acute and delayed clinical manifestations.
Resumo:
The behavior of T. cruzi strains from S. Felipe - BA (19 SF, 21 SF and 22 SF) classified as Type II Zymodeme 2, was investigated after passage through the authoctonous (P. megistus) and foreign vectors (T. infestans and R. prolixus). For each strain Swiss mice were infected: I - with blood forms (control); II - with metacyclic forms (MF) from P. megistus; III - with MF from T. infestans; IV - with MF from R. prolixus. Inocula: MF from the three species of triatomine, 60 to 120 days after feeding in infected mice, adjusted to 10 4. Biological behavior in mice (parasitemia, morphology, mortality, virulence and pathogenicity) after passage through triatomine was compared with data from the same strain in control mice. Isoenzymic electrophoresis (ASAT, ALAT, PGM, GPI) were also performed after culture into Warren medium. The three strains maintained the isoenzyme profiles (zymodeme 2), in the control groups and after passages through different species of triatomine. Biological characterization disclosed Type II strains patterns for all groups. An increased virulence was observed with the 22 SF strain isolated from P. megistus and T. infestans and higher levels of parasitemia and predominance of slender forms in mice inoculated with the 19 SF and 21 SF from these same species. Results indicate that the passage through the two species T. infestans and P. megistus had a positive influence on the virulence of the regional strains of S. Felipe, regardless of being autocthonous (P. megistus) or foreign to the area (T. infestans).
Resumo:
To investigate the possible role of domestic animals as reservoirs of human enteroviruses, we studied 212 stray dogs captured in different areas of the municipality of São Paulo. The captured animals were divided into 19 groups of 10 to 20 dogs each; faeces of 126 of the 212 dogs were processed for enterovirus isolation. The following viruses were isolated from 12 dogs: poliovirus type 1 (2 dogs), poliovirus type 3 (1 dog), echovirus type 7 (8 dogs) and echovirus type 15 (1 dog). Of the 12 infected animals, four had specific homotypic neutralizing antibody titres > 16. All 212 animals were tested for the presence of neutralizing antibodies to human enteroviruses. The frequency of neutralizing antibodies present in titres of > 16 was 10.3%, 3,8% and 4.3% for vaccinal prototypes of polioviruses 1, 2 and 3 respectively; 1,9%, 1.4% and 1.5% for wild prototypes of the same viruses, 11.3% for echovirus 7, and 2.4% for echovirus 15. The proportion of dogs with neutralizing antibodies varied with the virus studied. Some indication of the susceptibility of dogs to infection with human enteroviruses was demonstrated, and the importance of this fact for the Plan for Global Eradication of the Wild Poliovirus is discussed.
Resumo:
In order to obtain information on Brazilian spotted fever, a study in domestic animals was performed in the County of Pedreira, State of São Paulo, Brazil, where 17 human cases had been notified. Serum samples obtained from animals were tested by indirect immunofluorescence for detectable antibodies to spotted fever-group rickettsiae. Seropositivity was revealed in 12 (36.4%) of 33 dogs and seven (77.8%) of nine horses from the endemic area. For comparison, blood samples from dogs and horses from non endemic area were tested and four (12.9%) of 31 dogs and three (27.3%) of 11 horses were positive. The highest titers of antibodies by IFA (IgG > 1:1024) were found only in three dogs and six horses from endemic area. The results suggest that dogs as horses may serve as environmental sentinels for estabilishing the prevalence of foci of spotted fever in Brazil.
Resumo:
Epidemiologic and clinical aspects of 310 hospitalized snakebite patients and 310 matched controls were described, over a seven years period, from an emergency hospital in Belo Horizonte, Southeast Brazil. The diagnosis was based upon clinical picture or actual snake identification. Fifty six percent of victims were bitten by the snakes of genus Bothrops, 32.0% by Crotalus, 1.0% by Lachesis and 10.0% undetermined. During the study period, stable number of cases and marked seasonal variation were noted. In comparing cases of snakebite and controls, those from a rural area or who were involved in agricultural labor activity were identified as a high risk group, with an odds ratio (OR) of 14.7 and 6.7, respectively, in favor of being bitten. Upon treatment, snakebite patients were 13.5 times more likely to have had early anaphylactic reactions than their controls, with a higher association in the age group ³ 20 years (OR = 30.3). Increased risks were also detected for pyrexia (OR = 11.7), with a marked association in the group under 19 years old (OR = 16.6). Severe cases of snakebite are an important treatable cause of morbidity in Brazil but therapy may be potentially life threatening. The higher case-fatality ratio encountered, compared to national statistics may be due the representativeness of the more severe cases who sought hospitalization. Preventing snakebite and early referral of those who are bitten is proposed
Resumo:
The presence of Bertiella mucronata and Bertiella studeri (Cestoda: Anoplocephalidae) in humans is reviewed, and international infection rates and a bibliography included. Taxonomic, biological, epidemiological, pathological, diagnostic, control, prevention and therapeutic aspects of the zoonosis are analyzed, and the increase in zoonotic potentiality of the parasitosis is discussed