Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) wi... more Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) with humans is deeply grounded in immunology, from the diagnosis to pathogenesis, from the clinical presentations to the epidemiology, prevention, and treatment. However, the difficulty of capturing the complex and changeable array of immunological concepts and incorporating them into the strategies of control of the SARS-CoV-2 pandemic poses significant hindrances to establish optimal public health policies. The contribution of immunology to the control of the pandemic is to shed light on the features and mechanisms of the protective immunity elicited by SARS-CoV-2 infection and vaccines. Do they induce effective protective immunity? How? For how long? What is the effect of vaccination on individuals who were previously infected? To appropriately answer these questions, it is necessary to get rid of the outdated notion of a naïve, static, and closed immune system, which leads to misconcep...
The process of adaptation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to huma... more The process of adaptation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to humans probably had started decades ago, when its ancestor diverged from the bat coronavirus. The adaptive process comprises strategies the virus uses to overcome the respiratory tract defense barriers and replicate and shed in the host cells. These strategies include the impairment of interferon production, hiding immunogenic motifs, avoiding viral RNA detection, manipulating cell autophagy, triggering host cell death, inducing lymphocyte exhaustion and depletion, and finally, mutation and escape from immunity. In addition, SARS-CoV-2 employs strategies to take advantage of host cell resources for its benefits, such as inhibiting the ubiquitin-proteasome system, hijacking mitochondria functions, and usage of enhancing antibodies. It may be anticipated that as the tradeoffs of adaptation progress, the virus destructive burden will gradually subside. Some evidence suggests that SARS-CoV-2 will become part of the human respiratory virome, as had occurred with other coronaviruses, and coevolve with its host.
Revista da Sociedade Brasileira de Medicina Tropical, 2020
In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus di... more In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus disease (Covid-19) relies mainly on the adequacy of public health resources and policies. Hence, failure to establish and implement scientifically reliable control measures may have a significant effect on the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, severity of the disease, and death toll. The average number of secondary transmissions from an infected person, or reproduction numbers (R0 and R), and the points at which the collective immunity begins to reduce the transmission of the infection, or herd immunity thresholds, are important epidemiological tools used in strategies of Covid-19 control, suppression, and mitigation. However, SARS-CoV-2 transmission through asymptomatic carriers and, possibly, aerosols, has been ignored, and this may affect the effectiveness of Covid-19 control strategies. Therefore, consideration of the two possible ways...
Revista da Sociedade Brasileira de Medicina Tropical, 2009
Monocytes/macrophages play a critical role in the defense mechanisms against malaria parasites, a... more Monocytes/macrophages play a critical role in the defense mechanisms against malaria parasites, and are the main cells responsible for the elimination of malaria parasites from the blood circulation. We carried out a microscope-aided evaluation of the stages of in vitro phagocytosis of Plasmodium falciparum-infected erythrocytes, by human monocytes. These cells were obtained from healthy adult individuals by means of centrifugation through a cushion of Percoll density medium and were incubated with erythrocytes infected with Plasmodium falciparum that had previously been incubated with a pool of anti-plasmodial immune serum. We described the stages of phagocytosis, starting from adherence of infected erythrocytes to the phagocyte membrane and ending with their destruction within the phagolisosomes of the monocytes. We observed that the different erythrocytic forms of the parasite were ingested by monocytes, and that the process of phagocytosis may be completed in around 30 minutes. ...
Revista da Sociedade Brasileira de Medicina Tropical, 2021
Before eliciting an adaptive immune response, SARS-CoV-2 must overcome seven constitutive respira... more Before eliciting an adaptive immune response, SARS-CoV-2 must overcome seven constitutive respiratory defense barriers. The first is the mucus covering the respiratory tract's luminal surface, which entraps inhaled particles, including infectious agents, and eliminates them by mucociliary clearance. The second barrier comprises various components present in the airway lining fluid, the surfactants. Besides providing low surface tension that allows efficient gas exchange at the alveoli, surfactants inhibit the invasion of epithelial cells by respiratory viruses, enhance pathogen uptake by phagocytes, and regulate immune cells' functions. The respiratory tract microbiota constitutes the third defense barrier against SARS-CoV-2. It activates the innate and adaptive immune cells and elicits anti-infectious molecules such as secretory IgA antibodies, defensins, and interferons. The fourth defense barrier comprises the antimicrobial peptides defensins, and lactoferrin. They show direct antiviral activity, inhibit viral fusion, and modulate the innate and adaptive immune responses. Secretory IgA antibodies, the fifth defense barrier, besides protecting the local microbiota against noxious agents, also inhibit SARS-CoV-2 cell invasion. If the virus overcomes this barrier, it reaches its target, the respiratory epithelial cells. However, these cells also act as a defense barrier, the sixth one, since they hinder the virus' access to receptors and produce antiviral and immunomodulatory molecules such as interferons, lactoferrin, and defensins. Finally, the sensing of the virus by the cells of innate immunity, the last constitutive defense barrier, elicits a cascade of signals that activate adaptive immune cells and may inhibit the development of productive infection. The subject of the present essay is discussing these mechanisms.
Human organism is interpenetrated by the world of microorganisms, from the conception until the d... more Human organism is interpenetrated by the world of microorganisms, from the conception until the death. This interpenetration involves different levels of interactions between the partners including trophic exchanges, bi-directional cell signaling and gene activation, besides genetic and epigenetic phenomena, and tends towards mutual adaptation and coevolution. Since these processes are critical for the survival of individuals and species, they rely on the existence of a complex organization of adaptive systems aiming at two apparently conflicting purposes: the maintenance of the internal coherence of each partner, and a mutually advantageous coexistence and progressive adaptation between them. Humans possess three adaptive systems: the nervous, the endocrine and the immune system, each internally organized into subsystems functionally connected by intraconnections, to maintain the internal coherence of the system. The three adaptive systems aim at the maintenance of the internal coherence of the organism and are functionally linked by interconnections, in such way that what happens to one is immediately sensed by the others. The different communities of infectious agents that live within the organism are also organized into functional networks. The members of each community are linked by intraconnections, represented by the mutual trophic, metabolic and other influences, while the different infectious communities affect each other through interconnections. Furthermore, by means of its adaptive systems, the organism influences and is influenced by the microbial communities through the existence of transconnections. It is proposed that these highly complex and dynamic networks, involving gene exchange and epigenetic phenomena, represent major coevolutionary forces for humans and microorganisms.
Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) wi... more Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) with humans is deeply grounded in immunology, from the diagnosis to pathogenesis, from the clinical presentations to the epidemiology, prevention, and treatment. However, the difficulty of capturing the complex and changeable array of immunological concepts and incorporating them into the strategies of control of the SARS-CoV-2 pandemic poses significant hindrances to establish optimal public health policies. The contribution of immunology to the control of the pandemic is to shed light on the features and mechanisms of the protective immunity elicited by SARS-CoV-2 infection and vaccines. Do they induce effective protective immunity? How? For how long? What is the effect of vaccination on individuals who were previously infected? To appropriately answer these questions, it is necessary to get rid of the outdated notion of a naïve, static, and closed immune system, which leads to misconcep...
Revista da Sociedade Brasileira de Medicina Tropical
In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus di... more In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus disease (Covid-19) relies mainly on the adequacy of public health resources and policies. Hence, failure to establish and implement scientifically reliable control measures may have a significant effect on the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, severity of the disease, and death toll. The average number of secondary transmissions from an infected person, or reproduction numbers (R 0 and R), and the points at which the collective immunity begins to reduce the transmission of the infection, or herd immunity thresholds, are important epidemiological tools used in strategies of Covid-19 control, suppression, and mitigation. However, SARS-CoV-2 transmission through asymptomatic carriers and, possibly, aerosols, has been ignored, and this may affect the effectiveness of Covid-19 control strategies. Therefore, consideration of the two possible ways of transmission would substantially increase the values of reproduction numbers, but if estimates of the contingent of the population naturally resistant to the virus, plus those with pre-existing cross-immunity to SARS-CoV-2 were considered, the evaluation of herd immunity thresholds should reach their real and achievable levels.
Revista da Sociedade Brasileira de Medicina Tropical, 1967
Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e a... more Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e após inoculação de Schistosoma manroni e após terapêutica pelo aminonitrotiazol, os autores puderam observar, antes da inoculação, os seguinces valores: T-GP = 28.3, T-GO = 24,7. Os desvios padrões foram respectivamente de 11,2 e 11,3 e os valores extremos variaram para T-GO 10 e 60 µF e entre 15 e 57 µF para T-GP. Após inoculação, em apenas 1 caso puderam observar, 81 dias após, um valor para T-GP de 70 µF que pode ser considerado como discretamente aumentado. Não encontraram alterações após terapêutica pelo Cl 32.644 Ba (Aminonitrotiazol).
Revista da Sociedade Brasileira de Medicina Tropical
Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e a... more Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e após inoculação de Schistosoma m anroni e após tera pêutica pelo aminonitrotiazol, os autores puderam observar, antes da inoculação, os seguinces valores: T-GP = 28.3, T-GO = 24,7. Os desvios padrões foram res pectivam ente de 11,2 e 11,3 e os valores extremos variaram para T-GO 10 e 60 uF e entre 15 e 57 uF para T-GP. Após inoculação, em apenas 1 caso puderam observar, 81 dias após, um valor para T-GP de 70 uF que pode ser considerado como discretamente aumentado. Não encontraram alterações após terapêutica pelo Cl 32.644 Ba (Aminonitro tia zo l).
Revista da Sociedade Brasileira de Medicina Tropical, 1969
São apresentados os resultados preliminares ãe um estudo evolutivo da lo calização renal ãe compl... more São apresentados os resultados preliminares ãe um estudo evolutivo da lo calização renal ãe complexos antígeno-anticorpo solúveis em ratos infectados com P. berghei. Embora no 2P dia o animal já apresentasse parasitos circulan tes e no 6.° dia fôsse demonstrado anticorpos circulantes, somente no 12.° dia ficou caracterizada a presença simultânea de antígeno e anticorpo, por imunofluorescência, nos glomérulos e arteríolas renais, correspondendo a um a queaa do nível sérico de complemento. No 16.° dia o depósito glomerular era m í nimo e o complemento retornou a níveis considerados normais. Após um confronto com os dados obtidos em outros trabalhos o A. sugere que o P. berghei possa apresentar um a ação patogênica para o hospedeiro através da formação ãe complexos Ag-Ac embora acentuando a necessidade ãe estudos adicionais. * Trabalho da C línica de Doenças In fectu osaí e Parasitárias da F.M. da U.F.R.J. e do In stitu to Brasileiro de Tropicologia M édica, Cx. Postal 1859, Rio de Janejro. ** B olsista do C onselho N acional de P esquisas.
Revista do Instituto de Medicina Tropical de São Paulo
... en-demic areas submitted to natural infection, to-gether with the diversity of HLA ... be-twe... more ... en-demic areas submitted to natural infection, to-gether with the diversity of HLA ... be-tween low responsiveness to a synthetic merozite vaccine and HLA-DR4 antigen has been ... P. & CHÜLAY, JD:-Safety and efficacy of a 'recombinant DNA Plasmodium falciparum sporozoite ...
The Amazon region is known for the high occurrence of hepatitis B virus (HBV) infection, and acco... more The Amazon region is known for the high occurrence of hepatitis B virus (HBV) infection, and accounts for more than 98% of malaria cases in Brazil. Despite the controversy, it has been proposed that when associated they may lead to important effects in the natural history of both infections. This study estimates the prevalence of coinfection within general population of an endemic region of HBV and malaria in the Brazilian Amazon. The prevalence of HBsAg was 3.3% (95% CI 2.1%-5.1%,) and total anti-HBc 49.9% (95% CI 45.9%-53.8%). The prevalence of antibodies against Plasmodium vivax and Plasmodium falciparum antigens was 51.4% (311/605) (95% CI 47.3%-55.4%). Related to the simultaneous presence of malaria antibodies and HBV serological markers, in 1.8% (11/605), (95% CI 1.0%-3.3%), the presence of HBsAg was also demonstrated, mean age 26 years (p
Revista da Sociedade Brasileira de Medicina Tropical
Chronic septicemic salmonellosis is an individualized clinical entity characterized by prolonged ... more Chronic septicemic salmonellosis is an individualized clinical entity characterized by prolonged fever with enlargement of the liver and spleen that occurs in Schistosoma-infected individuals who are coinfected with Salmonella. Several immunopathogenic mechanisms are involved, and they depend on the peculiarities of the interactions between Salmonella and various species of the genus Schistosoma. The modifications to the immune system that are caused by parasite infection are responsible for the evolution of the disease. In this review, we analyze the evolution of the knowledge on this entity and discuss the possible immuno-physiopathogenic mechanisms that contribute towards its development.
Revista da Sociedade Brasileira de Medicina Tropical
In 1992 an investigation regarding the value of insecticide impregnated mosquito nets was conduct... more In 1992 an investigation regarding the value of insecticide impregnated mosquito nets was conducted in the municipality of Costa Marques, Rondonia. Impregnated mosquito nets gave similar protection to those not impregnated, without modifying the incidence of infection during the season of low transmission. The multivariate analysis for age and antibody titre showed a significant protection of impregnated nets against the risk of infection only in the season of high transmission, when bed nets were used more correctly. There was no difference in the effect of both kinds of bed nets in the prevention of high parasitaemia. At the end of the study, there was a reduction of the prevalence of splenomegaly in both groups but hematocrit values rose to normal in the below 15 year olds using impregnated nets.
Unstimulated peritoneal cells from C57Bl mice were allowed to phagocytose in vitro different mixt... more Unstimulated peritoneal cells from C57Bl mice were allowed to phagocytose in vitro different mixtures of Percoll-separated parasitized and non-parasitized erythrocytes (PE and NPE) from the blood of mice infected with Plasmodium yoelii in the presence of immune and normal serum. Immune serum caused a significant enhancement of phagocytosis, and both the number of PE adhering to and/or ingested by 100 macrophages and the number of the latter cells engaged in phagocytosis was increased. The effect of immune serum was more marked when the ratio of PE/macrophages was 5--40/1, but was less at a ratio of 80/1, when considerable phagocytosis of PE occurred in the presence of normal serum. From 83--100% of the phagocytosed cells were parasitized erythrocytes, even when the ratio of PE/NPE was as low as 1/15. In the system used, macrophages were unable to discriminate between non-parasitized erythrocytes from infected mice and normal erythrocytes. Eosinophils were also observed to engage in ...
Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) wi... more Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) with humans is deeply grounded in immunology, from the diagnosis to pathogenesis, from the clinical presentations to the epidemiology, prevention, and treatment. However, the difficulty of capturing the complex and changeable array of immunological concepts and incorporating them into the strategies of control of the SARS-CoV-2 pandemic poses significant hindrances to establish optimal public health policies. The contribution of immunology to the control of the pandemic is to shed light on the features and mechanisms of the protective immunity elicited by SARS-CoV-2 infection and vaccines. Do they induce effective protective immunity? How? For how long? What is the effect of vaccination on individuals who were previously infected? To appropriately answer these questions, it is necessary to get rid of the outdated notion of a naïve, static, and closed immune system, which leads to misconcep...
The process of adaptation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to huma... more The process of adaptation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to humans probably had started decades ago, when its ancestor diverged from the bat coronavirus. The adaptive process comprises strategies the virus uses to overcome the respiratory tract defense barriers and replicate and shed in the host cells. These strategies include the impairment of interferon production, hiding immunogenic motifs, avoiding viral RNA detection, manipulating cell autophagy, triggering host cell death, inducing lymphocyte exhaustion and depletion, and finally, mutation and escape from immunity. In addition, SARS-CoV-2 employs strategies to take advantage of host cell resources for its benefits, such as inhibiting the ubiquitin-proteasome system, hijacking mitochondria functions, and usage of enhancing antibodies. It may be anticipated that as the tradeoffs of adaptation progress, the virus destructive burden will gradually subside. Some evidence suggests that SARS-CoV-2 will become part of the human respiratory virome, as had occurred with other coronaviruses, and coevolve with its host.
Revista da Sociedade Brasileira de Medicina Tropical, 2020
In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus di... more In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus disease (Covid-19) relies mainly on the adequacy of public health resources and policies. Hence, failure to establish and implement scientifically reliable control measures may have a significant effect on the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, severity of the disease, and death toll. The average number of secondary transmissions from an infected person, or reproduction numbers (R0 and R), and the points at which the collective immunity begins to reduce the transmission of the infection, or herd immunity thresholds, are important epidemiological tools used in strategies of Covid-19 control, suppression, and mitigation. However, SARS-CoV-2 transmission through asymptomatic carriers and, possibly, aerosols, has been ignored, and this may affect the effectiveness of Covid-19 control strategies. Therefore, consideration of the two possible ways...
Revista da Sociedade Brasileira de Medicina Tropical, 2009
Monocytes/macrophages play a critical role in the defense mechanisms against malaria parasites, a... more Monocytes/macrophages play a critical role in the defense mechanisms against malaria parasites, and are the main cells responsible for the elimination of malaria parasites from the blood circulation. We carried out a microscope-aided evaluation of the stages of in vitro phagocytosis of Plasmodium falciparum-infected erythrocytes, by human monocytes. These cells were obtained from healthy adult individuals by means of centrifugation through a cushion of Percoll density medium and were incubated with erythrocytes infected with Plasmodium falciparum that had previously been incubated with a pool of anti-plasmodial immune serum. We described the stages of phagocytosis, starting from adherence of infected erythrocytes to the phagocyte membrane and ending with their destruction within the phagolisosomes of the monocytes. We observed that the different erythrocytic forms of the parasite were ingested by monocytes, and that the process of phagocytosis may be completed in around 30 minutes. ...
Revista da Sociedade Brasileira de Medicina Tropical, 2021
Before eliciting an adaptive immune response, SARS-CoV-2 must overcome seven constitutive respira... more Before eliciting an adaptive immune response, SARS-CoV-2 must overcome seven constitutive respiratory defense barriers. The first is the mucus covering the respiratory tract's luminal surface, which entraps inhaled particles, including infectious agents, and eliminates them by mucociliary clearance. The second barrier comprises various components present in the airway lining fluid, the surfactants. Besides providing low surface tension that allows efficient gas exchange at the alveoli, surfactants inhibit the invasion of epithelial cells by respiratory viruses, enhance pathogen uptake by phagocytes, and regulate immune cells' functions. The respiratory tract microbiota constitutes the third defense barrier against SARS-CoV-2. It activates the innate and adaptive immune cells and elicits anti-infectious molecules such as secretory IgA antibodies, defensins, and interferons. The fourth defense barrier comprises the antimicrobial peptides defensins, and lactoferrin. They show direct antiviral activity, inhibit viral fusion, and modulate the innate and adaptive immune responses. Secretory IgA antibodies, the fifth defense barrier, besides protecting the local microbiota against noxious agents, also inhibit SARS-CoV-2 cell invasion. If the virus overcomes this barrier, it reaches its target, the respiratory epithelial cells. However, these cells also act as a defense barrier, the sixth one, since they hinder the virus' access to receptors and produce antiviral and immunomodulatory molecules such as interferons, lactoferrin, and defensins. Finally, the sensing of the virus by the cells of innate immunity, the last constitutive defense barrier, elicits a cascade of signals that activate adaptive immune cells and may inhibit the development of productive infection. The subject of the present essay is discussing these mechanisms.
Human organism is interpenetrated by the world of microorganisms, from the conception until the d... more Human organism is interpenetrated by the world of microorganisms, from the conception until the death. This interpenetration involves different levels of interactions between the partners including trophic exchanges, bi-directional cell signaling and gene activation, besides genetic and epigenetic phenomena, and tends towards mutual adaptation and coevolution. Since these processes are critical for the survival of individuals and species, they rely on the existence of a complex organization of adaptive systems aiming at two apparently conflicting purposes: the maintenance of the internal coherence of each partner, and a mutually advantageous coexistence and progressive adaptation between them. Humans possess three adaptive systems: the nervous, the endocrine and the immune system, each internally organized into subsystems functionally connected by intraconnections, to maintain the internal coherence of the system. The three adaptive systems aim at the maintenance of the internal coherence of the organism and are functionally linked by interconnections, in such way that what happens to one is immediately sensed by the others. The different communities of infectious agents that live within the organism are also organized into functional networks. The members of each community are linked by intraconnections, represented by the mutual trophic, metabolic and other influences, while the different infectious communities affect each other through interconnections. Furthermore, by means of its adaptive systems, the organism influences and is influenced by the microbial communities through the existence of transconnections. It is proposed that these highly complex and dynamic networks, involving gene exchange and epigenetic phenomena, represent major coevolutionary forces for humans and microorganisms.
Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) wi... more Understanding the interactions of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) with humans is deeply grounded in immunology, from the diagnosis to pathogenesis, from the clinical presentations to the epidemiology, prevention, and treatment. However, the difficulty of capturing the complex and changeable array of immunological concepts and incorporating them into the strategies of control of the SARS-CoV-2 pandemic poses significant hindrances to establish optimal public health policies. The contribution of immunology to the control of the pandemic is to shed light on the features and mechanisms of the protective immunity elicited by SARS-CoV-2 infection and vaccines. Do they induce effective protective immunity? How? For how long? What is the effect of vaccination on individuals who were previously infected? To appropriately answer these questions, it is necessary to get rid of the outdated notion of a naïve, static, and closed immune system, which leads to misconcep...
Revista da Sociedade Brasileira de Medicina Tropical
In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus di... more In the absence of vaccines and effective antiviral drugs, control of the spread of coronavirus disease (Covid-19) relies mainly on the adequacy of public health resources and policies. Hence, failure to establish and implement scientifically reliable control measures may have a significant effect on the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, severity of the disease, and death toll. The average number of secondary transmissions from an infected person, or reproduction numbers (R 0 and R), and the points at which the collective immunity begins to reduce the transmission of the infection, or herd immunity thresholds, are important epidemiological tools used in strategies of Covid-19 control, suppression, and mitigation. However, SARS-CoV-2 transmission through asymptomatic carriers and, possibly, aerosols, has been ignored, and this may affect the effectiveness of Covid-19 control strategies. Therefore, consideration of the two possible ways of transmission would substantially increase the values of reproduction numbers, but if estimates of the contingent of the population naturally resistant to the virus, plus those with pre-existing cross-immunity to SARS-CoV-2 were considered, the evaluation of herd immunity thresholds should reach their real and achievable levels.
Revista da Sociedade Brasileira de Medicina Tropical, 1967
Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e a... more Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e após inoculação de Schistosoma manroni e após terapêutica pelo aminonitrotiazol, os autores puderam observar, antes da inoculação, os seguinces valores: T-GP = 28.3, T-GO = 24,7. Os desvios padrões foram respectivamente de 11,2 e 11,3 e os valores extremos variaram para T-GO 10 e 60 µF e entre 15 e 57 µF para T-GP. Após inoculação, em apenas 1 caso puderam observar, 81 dias após, um valor para T-GP de 70 µF que pode ser considerado como discretamente aumentado. Não encontraram alterações após terapêutica pelo Cl 32.644 Ba (Aminonitrotiazol).
Revista da Sociedade Brasileira de Medicina Tropical
Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e a... more Fazendo determinações dos níveis de transamino.se sérica (T-GP e T-GO) em Cebus apella, antes e após inoculação de Schistosoma m anroni e após tera pêutica pelo aminonitrotiazol, os autores puderam observar, antes da inoculação, os seguinces valores: T-GP = 28.3, T-GO = 24,7. Os desvios padrões foram res pectivam ente de 11,2 e 11,3 e os valores extremos variaram para T-GO 10 e 60 uF e entre 15 e 57 uF para T-GP. Após inoculação, em apenas 1 caso puderam observar, 81 dias após, um valor para T-GP de 70 uF que pode ser considerado como discretamente aumentado. Não encontraram alterações após terapêutica pelo Cl 32.644 Ba (Aminonitro tia zo l).
Revista da Sociedade Brasileira de Medicina Tropical, 1969
São apresentados os resultados preliminares ãe um estudo evolutivo da lo calização renal ãe compl... more São apresentados os resultados preliminares ãe um estudo evolutivo da lo calização renal ãe complexos antígeno-anticorpo solúveis em ratos infectados com P. berghei. Embora no 2P dia o animal já apresentasse parasitos circulan tes e no 6.° dia fôsse demonstrado anticorpos circulantes, somente no 12.° dia ficou caracterizada a presença simultânea de antígeno e anticorpo, por imunofluorescência, nos glomérulos e arteríolas renais, correspondendo a um a queaa do nível sérico de complemento. No 16.° dia o depósito glomerular era m í nimo e o complemento retornou a níveis considerados normais. Após um confronto com os dados obtidos em outros trabalhos o A. sugere que o P. berghei possa apresentar um a ação patogênica para o hospedeiro através da formação ãe complexos Ag-Ac embora acentuando a necessidade ãe estudos adicionais. * Trabalho da C línica de Doenças In fectu osaí e Parasitárias da F.M. da U.F.R.J. e do In stitu to Brasileiro de Tropicologia M édica, Cx. Postal 1859, Rio de Janejro. ** B olsista do C onselho N acional de P esquisas.
Revista do Instituto de Medicina Tropical de São Paulo
... en-demic areas submitted to natural infection, to-gether with the diversity of HLA ... be-twe... more ... en-demic areas submitted to natural infection, to-gether with the diversity of HLA ... be-tween low responsiveness to a synthetic merozite vaccine and HLA-DR4 antigen has been ... P. & CHÜLAY, JD:-Safety and efficacy of a 'recombinant DNA Plasmodium falciparum sporozoite ...
The Amazon region is known for the high occurrence of hepatitis B virus (HBV) infection, and acco... more The Amazon region is known for the high occurrence of hepatitis B virus (HBV) infection, and accounts for more than 98% of malaria cases in Brazil. Despite the controversy, it has been proposed that when associated they may lead to important effects in the natural history of both infections. This study estimates the prevalence of coinfection within general population of an endemic region of HBV and malaria in the Brazilian Amazon. The prevalence of HBsAg was 3.3% (95% CI 2.1%-5.1%,) and total anti-HBc 49.9% (95% CI 45.9%-53.8%). The prevalence of antibodies against Plasmodium vivax and Plasmodium falciparum antigens was 51.4% (311/605) (95% CI 47.3%-55.4%). Related to the simultaneous presence of malaria antibodies and HBV serological markers, in 1.8% (11/605), (95% CI 1.0%-3.3%), the presence of HBsAg was also demonstrated, mean age 26 years (p
Revista da Sociedade Brasileira de Medicina Tropical
Chronic septicemic salmonellosis is an individualized clinical entity characterized by prolonged ... more Chronic septicemic salmonellosis is an individualized clinical entity characterized by prolonged fever with enlargement of the liver and spleen that occurs in Schistosoma-infected individuals who are coinfected with Salmonella. Several immunopathogenic mechanisms are involved, and they depend on the peculiarities of the interactions between Salmonella and various species of the genus Schistosoma. The modifications to the immune system that are caused by parasite infection are responsible for the evolution of the disease. In this review, we analyze the evolution of the knowledge on this entity and discuss the possible immuno-physiopathogenic mechanisms that contribute towards its development.
Revista da Sociedade Brasileira de Medicina Tropical
In 1992 an investigation regarding the value of insecticide impregnated mosquito nets was conduct... more In 1992 an investigation regarding the value of insecticide impregnated mosquito nets was conducted in the municipality of Costa Marques, Rondonia. Impregnated mosquito nets gave similar protection to those not impregnated, without modifying the incidence of infection during the season of low transmission. The multivariate analysis for age and antibody titre showed a significant protection of impregnated nets against the risk of infection only in the season of high transmission, when bed nets were used more correctly. There was no difference in the effect of both kinds of bed nets in the prevention of high parasitaemia. At the end of the study, there was a reduction of the prevalence of splenomegaly in both groups but hematocrit values rose to normal in the below 15 year olds using impregnated nets.
Unstimulated peritoneal cells from C57Bl mice were allowed to phagocytose in vitro different mixt... more Unstimulated peritoneal cells from C57Bl mice were allowed to phagocytose in vitro different mixtures of Percoll-separated parasitized and non-parasitized erythrocytes (PE and NPE) from the blood of mice infected with Plasmodium yoelii in the presence of immune and normal serum. Immune serum caused a significant enhancement of phagocytosis, and both the number of PE adhering to and/or ingested by 100 macrophages and the number of the latter cells engaged in phagocytosis was increased. The effect of immune serum was more marked when the ratio of PE/macrophages was 5--40/1, but was less at a ratio of 80/1, when considerable phagocytosis of PE occurred in the presence of normal serum. From 83--100% of the phagocytosed cells were parasitized erythrocytes, even when the ratio of PE/NPE was as low as 1/15. In the system used, macrophages were unable to discriminate between non-parasitized erythrocytes from infected mice and normal erythrocytes. Eosinophils were also observed to engage in ...
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