47 resultados para Titulação de anticorpos
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Leishmania infantum and Trypanosoma cruzi are trypanosomatids of medical importance and are, respectively, the etiologic agents of visceral leishmaniasis (VL) and Chagas disease (CD) in Brazil. People infected with L. infantum or T. cruzi may develop asymptomatically, enabling the transmission of pathogens through blood transfusion and / or organs. The assessment of the infection by T. cruzi is included among the tests performed for screening blood donors in Brazil, however, there is no availability of tests for Leishmania. Serological tests for T. cruzi are very sensitive, but not specific, and may have cross-reactions with other microorganisms. Thus, the aim of this study was to determine the prevalence of Leishmania infection in blood donors and assess whether the serological test for T. cruzi detect L. infantum. Among the 300 blood samples from donors, discarded in 2011, 61 were T. cruzi positive, 203 were from donors with other infections and 36 were from handbags with low blood volume, but without infection. We also assessed 144 samples from donors without infections and able to donate blood, totaling 444 subjects. DNA was extracted from blood samples of all to perform quantitative PCR (qPCR) to detect Leishmania DNA. The buffy coat obtained from all samples was grown in Schneider medium supplemented and NNN. All samples were evaluated for the presence of anti-Leishmania antibody. The serological results indicate a percentage of 22% of Leishmania infection in blood samples obtained from discarded bags. A total of 60% of samples positive in ELISA for T. cruzi were negative by IFI, used as confirmatory test, ie 60% false positive for Chagas. Among these samples false positive for Chagas, 72% were positive by ELISA for Leishmania characterizing the occurrence of cross reaction between serologic assays. Of the 300 cultures performed, 18 grew parasites that were typed by qPCR and specific isoenzymes, found the species Leishmania infantum crops. Among the 18 cultures, 4 were purged from scholarships for low volume and all negative serology blood bank, thus demonstrating that there is a real risk of Leishmania transmission via transfusion. It is concluded that in an area endemic for leishmaniasis in Brazil, serological diagnosis performed to detect infection by T. cruzi among blood donors can identify infection by L. infantum and although cause false positive for Chagas, this cross-reactivity reduces the risk of Leishmania infection via blood transfusion, since tests are not applied specific detection of the parasite. In this way, there remains the need to discuss the implementation of a specific serological screening test for Leishmania in endemic countries such as Brazil
Resumo:
Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, a protozoan that has a cosmopolitan geographic distribution and low host specificity. Usually a benign and selflimiting, infection can manifest itself in a severe systemic becoming overwhelming in fetuses and patients with immunosuppression. Domestic fowl are considered one of the most important hosts in the epidemiology of toxoplasmosis, since they are potential sources of infection for humans, in addition to playing the role of important indicators of environmental contamination by oocysts of T. gondii. We studied the prevalence of infection by the protozoan in chickens of different breeding systems mesoregions from the states of Rio Grande do Norte and Paraiba: broilers from commercial farms (200/PB) and free-range chickens of small farms (322/RN and PB). Were standardized IFAT and ELISA techniques for detecting specific antibodies in blood samples of birds, and commercial kit was used to determine the prevalence by IHAT. There was no seropositive reaction by T. gondii in the samples of broilers tested, indicating that the particularities of intensive management limit the chances of infection for these animals. Among the hens, the frequency of IgG anti-T. gondii diagnosed by the techniques of IHAT, IFAT and ELISA, respectively, were 3.73% (12/322), 37.88% (122/322) and 40.37% (130/322), for both young and adult animals. Amongst the seropositive samples by IFAT, 33 (27.05%) were positive at a dilution of 1:16, in 1:32, 31 (25.41%), in 1:64, 24 (19.67%), 15 (12.29%) in 1:128, and 19 presented titer greater than or equal to 1:256 (15.57%). The evaluation of the presence of anti-T. gondii should be careful, and reagents IHAT provided erratic results in this measure for the specie studied. This suggests the need for own standardization of the kit before the use in epidemiological studies in animal species. On the other hand, substantial agreement observed between IFAT and ELISA techniques (Kappa = 0.62) enables these methods as effective methodologies for the diagnosis of toxoplasmosis in chickens. The high prevalence of specific antibodies among poultry in the region studied attempts to the potential risk of transmission of toxoplasmosis to humans
Resumo:
Leishmania infantum and Trypanosoma cruzi are trypanosomatids of medical importance and are, respectively, the etiologic agents of visceral leishmaniasis (VL) and Chagas disease (CD) in Brazil. People infected with L. infantum or T. cruzi may develop asymptomatically, enabling the transmission of pathogens through blood transfusion and / or organs. The assessment of the infection by T. cruzi is included among the tests performed for screening blood donors in Brazil, however, there is no availability of tests for Leishmania. Serological tests for T. cruzi are very sensitive, but not specific, and may have cross-reactions with other microorganisms. Thus, the aim of this study was to determine the prevalence of Leishmania infection in blood donors and assess whether the serological test for T. cruzi detect L. infantum. Among the 300 blood samples from donors, discarded in 2011, 61 were T. cruzi positive, 203 were from donors with other infections and 36 were from handbags with low blood volume, but without infection. We also assessed 144 samples from donors without infections and able to donate blood, totaling 444 subjects. DNA was extracted from blood samples of all to perform quantitative PCR (qPCR) to detect Leishmania DNA. The buffy coat obtained from all samples was grown in Schneider medium supplemented and NNN. All samples were evaluated for the presence of anti-Leishmania antibody. The serological results indicate a percentage of 22% of Leishmania infection in blood samples obtained from discarded bags. A total of 60% of samples positive in ELISA for T. cruzi were negative by IFI, used as confirmatory test, ie 60% false positive for Chagas. Among these samples false positive for Chagas, 72% were positive by ELISA for Leishmania characterizing the occurrence of cross reaction between serologic assays. Of the 300 cultures performed, 18 grew parasites that were typed by qPCR and specific isoenzymes, found the species Leishmania infantum crops. Among the 18 cultures, 4 were purged from scholarships for low volume and all negative serology blood bank, thus demonstrating that there is a real risk of Leishmania transmission via transfusion. It is concluded that in an area endemic for leishmaniasis in Brazil, serological diagnosis performed to detect infection by T. cruzi among blood donors can identify infection by L. infantum and although cause false positive for Chagas, this cross-reactivity reduces the risk of Leishmania infection via blood transfusion, since tests are not applied specific detection of the parasite. In this way, there remains the need to discuss the implementation of a specific serological screening test for Leishmania in endemic countries such as Brazil
Resumo:
VITULLO, Nadia Aurora Vanti. Avaliação do banco de dissertações e teses da Associação Brasileira de Antropologia: uma análise cienciométrica. 2001. 143 f. Dissertaçao (Mestrado) - Curso de Mestrado em Biblioteconomia e Ciência da Informação, Pontifícia Universidade Católica de Campinas, Campinas, 2001.
Resumo:
AZEVEDO, Luciana Karla Araújo de, et al. Caracterização e correlação do fenômeno pró-zona com títulos de sororeatividade do VDRL e reação de imuno-fluorescência indireta em soros de pacientes com sífilis. Revista Brasileira de Análises Clínicas, Rio de Janeiro, v. 38, n. 2, p. 183-187, 2006.
Resumo:
American visceral leishmaniasis is a zoonosis caused by Leishmania infantum and transmitted by the bite of the sand flies Lutzomia longipalpis.The main domestic reservoir is the dog, while foxes and opposums are the known wild reservoirs. However, identification of natural infections with L. infantum in rodents appears for need of investigating the participation of these rodents how source of infection of the parasite. In the present work the Leishmania infantum infection was investigated in rodents captured in Rio Grande do Norte, aiming at to offer subsidies to the understanding of the epidemic chains of LVA in the State. Thirteen Galea spixii were distributed in four groups, being G1 the group control with four animals and the others, G2, G3 and G4, with three animals each. Those animals were intraperitoneally inoculated with 107 promastigotas of L. infantum and accompanied for, respectively, 30, 90 and 180 days. Weekly the animals were monitored as for the corporal weight and rectal temperature. At the end of each stipulated period the animals were killed. Blood were used for determination of the parameters biochemical and haematological, PCR, ELISA, microscopic examination and cultivation in NNN medium. Liver, spleen and lymph node were used in Giemsa-stained impression and cultivation in NNN medium. Liver and spleen fragments were still used in PCR and histopathological, respectively. At the same time 79 rodents of the species Rattus rattus, Bolomys lasiurus, Oligoryzomys nigripis, Oryzomys subflavus and Trichomys apereoides were captured in the Municipal districts of Brejinho, Campo Grande, Coronel Ezequiel, Passa e Fica and Vázea for identification of natural infection with L. infantum. Evidence of infection was checked by direct examination of Giemsa-stained impression of liver, spleen and blood and culture of these tissues in NNN medium. Antibodies were researched by ELISA. They were not found differences among the weigh corporal final, rectal temperature and biochemical and haematological parameters of the Galea spixii controls and infected. The rectal temperature of the animals varied from 36OC to 40OC. For the first time values of the haematocrit (33,6% to 42,8%), hemoglobin (10,2 to 14,5g/dl), erythrocyts number (4,67x106 to 6,90x106/mm3), total leukocytes (0,9x103 to 9,2x103/mm3), platelets (49x103 to 509x103/mm3) total proteins (1,56 to 6,06 g/dl), albumin (1,34 to 3,05 g/dl) and globulins (0,20 to 3,01 g/dl) of the Galea spixii were determined. The lymphocytes were the most abundant leucocytes. Infection for L. infantum was diagnosed in two animals euthanasied 180 days after the infection. In one of the animals was also identified antibodies anti-Leishmania. The parasite was not found in none of the five other species of rodents captured. Galea spixii are resistant to the infection for L. infantum and they are not good models for the study for visceral leishmaniose, although they can act as infection sources. More studies are necessary to determine the paper of the rodents in the epidemic chain of transmission of the visceral leishmaniose in the State of Rio Grande do Norte
Resumo:
Nutritional status is an important determinant to the response against Leishmania infection, although few studies have characterized the molecular basis for the association found between malnutrition and the disease. Vitamin A supplementation has long been used in developing countries to prevent mortality by diarrheal and respiratory diseases, but there are no studies on the role of vitamin A in Leishmania infection, although we and others have found vitamin A deficiency in visceral Leishmaniasis (VL). Regulatory T cells are induced in vitro by vitamin A metabolites and are considered important cells implicated T CD4+ cell suppression in human VL. This work aimed to examine the correlation of nutritional status and the effect of vitamin A in the response against Leishmania infantum infection. A total of 179 children were studied: 31 had active VL, 33 VL history, 44 were DTH+ and 71 were DTH- and had negative antibody to Leishmania (DTH-/Ac-). Peripheral blood monuclear cells were isolated in a subgroup of 10 active VL and 16 DTH-/Ac- children and cultivated for 20h under 5 different conditions: 1) Medium, 2) Soluble promastigote L. infantum antigens (SLA), 3) All-trans retinoic acid (ATRA), 4) SLA + ATRA and 5) Concanavalin A. T CD4+CD25highFoxp3+, T CD4+CD25-Foxp3- and CD14+ monocytes were stained and studied by flow cytometry for IL-10, TGF-β and IL-17 production. Nutritional status was compromised in VL children, which presented lower BMI/Age and retinol concentrations when compared to healthy controls. We found a negative correlation between nutritional status (measured by BMI/Age and serum retinol) and anti-Leishmania antibodies and acute phase proteins. There was no correlation between nutritional status and parasite load. ATRA presented a dual effect in Treg cells and monocytes: In healthy children (DTH-/Ac-), it induced a regulatory response, increasing IL-10 and TGF-β production; in VL children it modulated the immune response, preventing increased IL-10 production after SLA stimulation. Furthermore, we found a positive correlation between BMI/Age and IL-17 production and negative correlation between serum retinol and IL-10 and TGF-β production in T CD4+CD25highFoxp3+ cells after SLA stimulus. Our results show a potential dual role of vitamin A in the immune system: improvement of regulatory profile during homeostasis and down modulation of IL-10 in Treg cells and monocytes during symptomatic VL. Therefore, the use of vitamin A concomitant to VL therapy might improve recovery from disease status in Leishmania infantum infection
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Resumo:
The materials engineering includes processes and products involving several areas of engineering, allowing them to prepare materials that fulfill the needs of various new products. In this case, this work aims to study a system composed of cement paste and geopolymers, which can contribute to solving an engineering problem that directly involves the exploitation of oil wells subject to loss of circulation. To correct it, has been already proposed the use of granular materials, fibers, reducing the drilling fluid or cement paste density and even surface and downhole mixed systems. In this work, we proposed the development of a slurry mixed system, the first was a cement-based slurry and the second a geopolymer-based slurry. The cement-based slurry was formulated with low density and extenders, 12.0 ppg (1.438 g/cm ³), showing great thixotropic characteristics. It was added nano silica at concentrations of 0.5, 1.0 and 1.5 gps (66.88, 133.76 and 200.64 L/m3) and CaCl2 at concentrations of 0.5, 1, 0 and 1.5%. The second system is a geopolymer-based paste formulated from molar ratios of 3.5 (nSiO2/nAl2O3), 0.27 (nK2O/nSiO2), 1.07 (nK2O/nAl2O3) and 13.99 (nH2O/nK2O). Finally, we performed a mixture of these two systems, for their application for correction of circulation lost. To characterize the raw materials, XRD, XRF, FTIR analysis and titration were performed. The both systems were characterized in tests based on API RP10B. Compressive strength tests were conducted after curing for 24 hours, 7 and 28 days at 58 °C on the cement-based system and the geopolymer-based system. From the mixtures have been performed mixability tests and micro structural characterizations (XRD, SEM and TG). The results showed that the nano silica, when combined with CaCl2 modified the rheological properties of the cement slurry and from the concentration of 1.5 gpc (200.64 L / m³) it was possible to obtain stable systems. The system mixture caused a change in the microstructure of the material by favoring the rate of geopolymer formation to hinder the C3S phase hydration, thus, the production of CSH phases and Portlandite were harmed. Through the mixability tests it can be concluded that the system, due to reduced setting time of the mixture, can be applied to plug lost circulation zones when mixed downhole
Resumo:
Toxoplasmosis is one zoonosis caused by Toxoplasma gondii protozoan. Goats, amongst the production animals, are one of the species most susceptible to this parasite, being one them main involved agents in ovine and goat abortions, determining great economic losses and implications for public health, since the presence it parasite in the products of goat origin, consist in one of the main sources of infection for the man. In this study 244 blood samples in 8 farms situated in 4 cities from the Sertão do Cabugi region, Rio Grande do Norte State, northeast of Brazil and, tested by ELISA assay. The results had shown a prevalence of 47.13% for anti- T. gondii antibodies and a significant association between positivity and variable evaluated as age, locality and property. The IgG avidity assay evaluated in 115 positive samples was carried to discriminate acute and chronic infection. Twelve samples (10.4%) had presented antibodies of low avidity while 103 (89.6%) presented high avidity antibodies; indicating that most of the animals was precocious exposure to the parasite. Significant difference was verified only for the variable sex. We also evaluate the capacity of recombinant adenoviruses codifying SAG1, SAG2, SAG3 and CMV in inducing activation of specific immune response in goat. These 109 animals received 109 pfu of the AdSAG1, AdSAG2, AdSAG3, AdCMV or PBS in vaccine protocol with 3 immunizations. Serum samples of the each animal, before and after mmunization, had been submitted to the ELISA. The results demonstrate that the immunizations had induced the production of IgG antibodies specific against T. gondii proteins
Resumo:
Toxoplasmosis, provoked by the intracellular parasite Toxoplasma gondii, is one of the most prevalent parasitoses in the world. In humans, transmission occurs by three evolutionary forms of the parasite: oocysts, tissue cysts and tachyzoites. Wild and domestic felines are definitive hosts. The ocular form of toxoplasmosis can be of congenital origin with early or late clinical manifestations, or acquired after birth. T. gondii is considered the main culprit for most cases of infectious uveitis. This study aimed at assessing ocular toxoplasmosis, relating it to factors associated to the patient s lifestyle and describing the epidemic-serological and clinical profile of affected individuals. A cross-sectional study was conducted with a population of 159 patients. Univariate analysis (odds ratio) was used to evaluate the data, with a confidence interval of 95% and p-value < 0.05. A prevalence of 4% of ocular toxoplasmosis was observed in the population of patients treated at an ophthalmological clinic. Of patients directly examined by immunoenzymatic assay (MEIA-AxSYM®- Microparticle Enzyme Immune Assay), considering only uveitis, a frequency of anti-T. gondii of 73%, most of whom exhibited titulation between 40-99 UI IgG/mL. With respect to location of ocular lesions, bilaterality was observed in 57% of patients assessed by the ophthalmoscopy technique. When compared with the results of an active search of medical records, a similarity in ocular toxoplasmosis (74%) and bilateral lesion location (55%) was observed. Type I lesion was the most frequent type observed, with intraocular disposition in the macula. An epidemiological survey revealed that direct contact with cats; consuming raw or poorly cooked meat and direct contact with the soil were significantly associated with greater likelihood of acquiring ocular toxoplasmosis. Sample characterization in relation to age range was significant for patients between 31 and 40 years [χ², chi-square test (p = 0.04)], but population traits such as schooling, sanitary district, and monthly income were not significant. Results confirm that ocular toxoplasmosis is widely distributed in the metropolitan area of Natal, Brazil, with significant prevalence of ocular lesions provoked by T.gondii. It is suggested that sanitary authorities exert greater control in order to minimize the risk of toxoplasmic infection, mainly in pregnant women.
Resumo:
Toxoplasmosis is a zoonosis of worldwide distribution caused by the protozoan Toxoplasma gondii, triggering dangerous complications in immunocompromised patients and pregnant women, as well as having great economic impact for the livestock. So far the control of toxoplasmosis is made primarily by chemotherapy. However, most drugs used routinely have some limitations. In order to control this disease, several research groups, including ours, has been working to develop a medical-veterinary vaccine based on parasite antigens, vectors and protocols of immunization. In this study were implemented and standardized methodologies for amplification and cloning of recombinant immunogens in the system for the development of a prototype vaccine, based on the surface antigens of T. gondii and recombinant adenovirus encoding these antigens. Genes encoding BAG1, GRA2 and SAG1 proteins were amplified. We established a strategy for cloning SAG1, SAG2, SAG3 and TgAMA1- genes in recombinant system. The genes encoding SAG1 and SAG2 were cloned and their sequences showed high similarity with sequences from GenBank. The virtual translation of these proteins showed polymorphisms in the amino acid sequence, which can be correlated with levels of antigenicity. Simultaneously, the adenovirus encoding the SAGs (HAdSAGs) were expanded, purificated and characterizated. Immunization of C57bl/6 mice, using viral supernatant was not enought to elicit immune responses at high levels, being required HAdSAGs titration for future immunizations. Therefore, this study allowed the cloning of the two genes important for the development of a prototype vaccine. Besides, implementations methodologies that permit advancements in the development of a vaccine against toxoplasmosis using adenovirus to express proteins of the parasite
Resumo:
Visceral leishmaniasis hás adapted in the past 20 years to periurban and urban areas, and in Natal, Rio Grande do Norte, it became endemic. Thid study aimed to evaluate the environmental and social aspectsof Leishmania chagasi infection and its epidemiologic transmission chain in an urban, periurban and rural area of Parnamirim-RN. A study with three sections was conducted: Section 1: Sectional study of the human and canine infection by L. chagasi and its environmental and social determinants. Section 2: Observational longitudinal cohort to evaluate the dynamics of the canine infection. Section 3: Longitudinal study to evaluate the behavior of Lu. Longipalpis vector and the seasonal factors related to its dynamics. To include in the study the hauses were randomly selected and georreferenciated. Montenegro skin test was done in the human population and blood samples were collected for anti-Leishmania antibody detection. The canine population was examinated for L. chagasi infection by RIFI, ELISA and ELISA for rK39. An entomologic surveillance was monthly done with CDC light trapsin 10 houses of each locality. Quantitative and qualitative analyses was done using STATISC 6.0. Probality and prediction maps were done using ArcGis 9.0 model. In the human population L. chagasi infection was associated with the area of the hause, age, sex, population densyti, vegetation, kind of the floor of thr hause, water and resides destiny. In the canine population L. chagasi infection was associated with the breed, size, time of living in the hause, presence of dogs in the neighborhood, presence of horses and donkeys in the neighborhood, vegetation, kind of the floor and walls of the hause. The human infection was associated with canine infction only when analyzed taking into account the locality. In the prospective study, serum conversion and antibody lost observed in 30,8% and 22% of the animals examined, respectively. The human infection rate by L. chagasi was 24,6%, by the presence of anti-Leishmania antibody and 38,6% by the Montenegro skin test. The canine infection rate 32,5% by the presence of anti-Leishmania antibody. The vector Lu longipalpis showed an atypical behavior. These results indicate that environmental and social factors are important variables associated with L. chagasi infection in humans and canines, with punctual association of thr last two. Control measures of the infection on the studied points are necessary, in the aim to reduce the endemic focus of the disease in the study area. This research was carried out in a multidisciplinary involving the categories of: doctor, biologist, veterinarian, statistical, pharmaceutical and biochemical
Resumo:
O baço, como maior órgão linfóide do corpo humano, desempenha funções imunológicas relevantes, tais como depuração de bactérias da corrente sangüínea, produção de anticorpos e interação com a função hepática. A esplenectomia tem sido evitada sempre que possível, mas quando realizada pode provocar uma série de efeitos indesejáveis. O radiofármaco 99mTc-fitato é usado no diagnóstico de doenças, especialmente no fígado, através de exames de imagem, na dependência de sua biodistribuição. Algumas drogas e intervenções cirúrgicas podem interferir na biodistribuição de radiofármacos e inexistem na literatura dados sobre efeitos da esplenectomia no metabolismo do 99mTc-fitato. O objetivo do trabalho foi avaliar se a esplenectomia interfere na biodistribuição hepática do 99mTc-fitato e na função do fígado em ratos Wistar. Sob anestesia e técnica asséptica, os animais do grupo SP (n=6) foram esplenectomizados. No grupo C (controle; n=6) os animais não foram operados. Após 15 dias de observação, foi injetado de 0,1ml de 99mTc-fitato via plexo orbital (0,66MBq) em todos os animais. Após 30 minutos, foram retiradas amostras hepáticas para determinação do percentual de radioatividade/grama (% ATI/g), usando-se contador gama Wizard Perkin-Elmer. Realizou-se dosagem sérica de ALT, AST e LDH, e leucometria. Estatística pelo teste t, com significância de p>0,05. Observou-se diferença significativa (p=0,034) comparando-se o %ATI/g no fígado dos ratos esplenectomizados (0,990,2) com os controles (0,400,2). ALT, AST e LDH tiveram dosagens significativamente menores e houve leucocitose nos esplenectomizados (p=0,01), comparando-se com os controles. Concluiu-se que, em ratos, a esplenectomia provavelmente provocou alteração na captação de 99mTc-fitato pelo fígado, coincidindo com alterações na função hepática. A realização deste estudo teve caráter multidisciplinar, envolvendo pesquisadores de diversas áreas como Medicina Nuclear, Cirurgia, Análises Clínicas e Estatística. Este aspecto preencheu os requisitos da multidisciplinaridade do Programa de Pós-graduação em Ciências da Saúde
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico