Use of MALDI-TOF for identification and surveillance of gramnegative bacteria in captive wild psittacines / Uso do MALDI-TOF para identificação e monitoramento de bactérias Gram negativas em psitacídeos cativos

Microbiological studies of the sanitary and health status of psittacine birds that will be reintroduced is important in evaluating whether these animals act as carriers of pathogenic agents to other animals and humans. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a faster and more accurate method to identify bacteria than conventional microbiology methods. The aim of this study was to evaluate the health status of psittacines housed in captivity, by assessment of Gram-negative bacteria from fecal microbiota through MALDI- TOF MS identification. The results indicate high frequency of Gram-negative bacteria in feces (96.5%), especially from the Enterobacteriaceae family (88.7%). The most prevalent bacteria were Escherichia coli (39.0%), Proteus vulgaris (12.2%), Klebsiella spp. (12.1%) and Raoultella ornithinolytica (8.7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. and Escherichia hermannii were isolated with lower frequency. . All these agents are potentially pathogenic for parrots and can cause systemic infections in other animals and humans. These findings reinforce that MALDI- TOF MS proved to be a rapid and accurate method of identification of the microorganism and evaluation of the health status of psittacines, providing relevant data to assist decision-making regarding the sanitary protocols in wildlife centers, and possible future reintroduction of wild birds.

Estudos microbiológicos da sanidade de psitacídeos que serão reintroduzidos são importantes para avaliar se esses animais atuam como portadores de agentes patogênicos para outros animais e humanos. A espectrometria de massa por ionização/dessorção de matriz assistida por laser/tempo de vôo (MALDI-TOF MS) é um método mais rápido e preciso para identificar bactérias na comparação com métodos convencionais de microbiologia. O objetivo deste estudo foi avaliar o estado de saúde de psitacídeos cativos, identificando bactérias Gram-negativas da microbiota fecal por MALDI -TOF MS. Os resultados indicaram alta frequência de bactérias Gram-negativas nas fezes (96,5%), principalmente da família Enterobacteriaceae (88,7%). As mais prevalentes foram Escherichia coli (39,0%), Proteus vulgaris (12,2%), Klebsiella spp. (12,1%) e Raoultella ornithinolytica (8,7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. e Escherichia hermannii foram isolados com menor frequência. Todos esses agentes são potencialmente patogênicos para os papagaios e podem causar infecções sistêmicas em outros animais e seres humanos. Esses achados reforçam que o MALDI- TOF MS é um método rápido e preciso de identificação do microrganismo e avaliação do estado de saúde dos psitacídeos, fornecendo dados relevantes para auxiliar na tomada de decisões sobre os protocolos sanitários em centros de triagem de animais selvagens e sobre a possibilidade de reintrodução futura.

Use of MALDI-TOF for identification and surveillance of gram-negative bacteria in captive wild psittacines

Abstract Microbiological studies of the sanitary and health status of psittacine birds that will be reintroduced is important in evaluating whether these animals act as carriers of pathogenic agents to other animals and humans. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a faster and more accurate method to identify bacteria than conventional microbiology methods. The aim of this study was to evaluate the health status of psittacines housed in captivity, by assessment of Gram-negative bacteria from fecal microbiota through MALDI- TOF MS identification. The results indicate high frequency of Gram-negative bacteria in feces (96.5%), especially from the Enterobacteriaceae family (88.7%). The most prevalent bacteria were Escherichia coli (39.0%), Proteus vulgaris (12.2%), Klebsiella spp. (12.1%) and Raoultella ornithinolytica (8.7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. and Escherichia hermannii were isolated with lower frequency. . All these agents are potentially pathogenic for parrots and can cause systemic infections in other animals and humans. These findings reinforce that MALDI- TOF MS proved to be a rapid and accurate method of identification of the microorganism and evaluation of the health status of psittacines, providing relevant data to assist decision-making regarding the sanitary protocols in wildlife centers, and possible future reintroduction of wild birds.

Resumo Estudos microbiológicos da sanidade de psitacídeos que serão reintroduzidos são importantes para avaliar se esses animais atuam como portadores de agentes patogênicos para outros animais e humanos. A espectrometria de massa por ionização/dessorção de matriz assistida por laser/tempo de vôo (MALDI-TOF MS) é um método mais rápido e preciso para identificar bactérias na comparação com métodos convencionais de microbiologia. O objetivo deste estudo foi avaliar o estado de saúde de psitacídeos cativos, identificando bactérias Gram-negativas da microbiota fecal por MALDI -TOF MS. Os resultados indicaram alta frequência de bactérias Gram-negativas nas fezes (96,5%), principalmente da família Enterobacteriaceae (88,7%). As mais prevalentes foram Escherichia coli (39,0%), Proteus vulgaris (12,2%), Klebsiella spp. (12,1%) e Raoultella ornithinolytica (8,7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. e Escherichia hermannii foram isolados com menor frequência. Todos esses agentes são potencialmente patogênicos para os papagaios e podem causar infecções sistêmicas em outros animais e seres humanos. Esses achados reforçam que o MALDI- TOF MS é um método rápido e preciso de identificação do microrganismo e avaliação do estado de saúde dos psitacídeos, fornecendo dados relevantes para auxiliar na tomada de decisões sobre os protocolos sanitários em centros de triagem de animais selvagens e sobre a possibilidade de reintrodução futura.

Use of MALDI-TOF for identification and surveillance of gram-negative bacteria in captive wild psittacines / Uso do MALDI-TOF para identificação e monitoramento de bactérias Gram-negativas em psitacídeos cativos

Microbiological studies of the sanitary and health status of psittacine birds that will be reintroduced is important in evaluating whether these animals act as carriers of pathogenic agents to other animals and humans. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a faster and more accurate method to identify bacteria than conventional microbiology methods. The aim of this study was to evaluate the health status of psittacines housed in captivity, by assessment of Gram-negative bacteria from fecal microbiota through MALDI- TOF MS identification. The results indicate high frequency of Gram-negative bacteria in feces (96.5%), especially from the Enterobacteriaceae family (88.7%). The most prevalent bacteria were Escherichia coli (39.0%), Proteus vulgaris (12.2%), Klebsiella spp. (12.1%) and Raoultella ornithinolytica (8.7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. and Escherichia hermannii were isolated with lower frequency. . All these agents are potentially pathogenic for parrots and can cause systemic infections in other animals and humans. These findings reinforce that MALDI- TOF MS proved to be a rapid and accurate method of identification of the microorganism and evaluation of the health status of psittacines, providing relevant data to assist decision-making regarding the sanitary protocols in wildlife centers, and possible future reintroduction of wild birds.

Estudos microbiológicos da sanidade de psitacídeos que serão reintroduzidos são importantes para avaliar se esses animais atuam como portadores de agentes patogênicos para outros animais e humanos. A espectrometria de massa por ionização/dessorção de matriz assistida por laser/tempo de vôo (MALDI-TOF MS) é um método mais rápido e preciso para identificar bactérias na comparação com métodos convencionais de microbiologia. O objetivo deste estudo foi avaliar o estado de saúde de psitacídeos cativos, identificando bactérias Gram-negativas da microbiota fecal por MALDI -TOF MS. Os resultados indicaram alta frequência de bactérias Gram-negativas nas fezes (96,5%), principalmente da família Enterobacteriaceae (88,7%). As mais prevalentes foram Escherichia coli (39,0%), Proteus vulgaris (12,2%), Klebsiella spp. (12,1%) e Raoultella ornithinolytica (8,7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. e Escherichia hermannii foram isolados com menor frequência. Todos esses agentes são potencialmente patogênicos para os papagaios e podem causar infecções sistêmicas em outros animais e seres humanos. Esses achados reforçam que o MALDI- TOF MS é um método rápido e preciso de identificação do microrganismo e avaliação do estado de saúde dos psitacídeos, fornecendo dados relevantes para auxiliar na tomada de decisões sobre os protocolos sanitários em centros de triagem de animais selvagens e sobre a possibilidade de reintrodução futura.

Controle de qualidade analítica dos métodos utilizados para a detecção de protozoários patogênicos em amostras de água / Control of the analytic quality of the methods used for the detection of pathogenic protozoans in water samples

As espécies de protozoários patogênicos de veiculação hídrica Giardia spp. e Cryptosporidium spp. foram responsáveis por cerca 90% dos surtos de gastroenterite ocorridos nos últimos 25 anos, em vários países. Critérios de avaliação das etapas referentes à detecção destes agentes em amostras de água, tais como: precisão inicial, inoculação nas amostras em água bruta e, diagnóstico e localização de erros estão abordados neste trabalho. Estes critérios devem ser correntemente aplicados e constantemente avaliados pelos laboratórios, a fim de assegurar a confiabilidade dos resultados obtidos durante um monitoramento e, assim, fornecer subsídios para uma avaliação do risco de surtos.

The waterborne pathogenic protozoan species Giardia spp. and Cryptosporidium spp. have been responsible for the majority (90%) of the gastroenteritis outbreaks that have occurred in the last 25 years in various countries. This paper discusses evaluation criteria pertaining to the steps involved in the detection of these microorganisms in water samples, such as: initial precision, inoculation in environmental samples, diagnosis and error localization. These criteria should be often applied and evaluated by laboratories in order to assure the reliability of the results obtained in a program of monitoring, thus aiding in the evaluation of the risks of outbreaks.

Changes in sodium appetite evoked by lesions of the commissural nucleus of the tractus solitarius

Ablation of the area postrema/caudal nucleus of the tractus solitarius (NTS) complex increases sodium intake, but the effect of selective lesions of the caudal NTS is not known. We measured depletion-induced sodium intake in rats with electrolytic lesions of the commissural NTS that spared the area postrema. One day after the lesion, rats were depleted of sodium with furosemide (10 mg/kg body weight, sc) and then had access to water and a sodium-deficient diet for 24 h when 1.8 percent NaCl was offered. Water and saline intakes were measured for 2 h. Saline intake was higher in lesioned than in sham-lesioned rats (mean ± SEM: 20 ± 2 vs 11 ± 3 mL/2 h, P < 0.05, N = 6-7). Saline intake remained elevated in lesioned rats when the tests were repeated 6 and 14 days after the lesion, and water intake in these two tests was increased as well. Water intake seemed to be secondary to saline intake both in lesioned and in sham-lesioned rats. A second group of rats was offered 10 percent sucrose for 2 h/day before and 2, 7, and 15 days after lesion. Sucrose intake in lesioned rats was higher than in sham-lesioned rats only 7 days after lesioning. A possible explanation for the increased saline intake in rats with commissural NTS lesions could be a reduced gastrointestinal feedback inhibition. The commissural NTS is probably part of a pathway for inhibitory control of sodium intake that also involves the area postrema and the parabrachial nucleus.

Copepod parasites of Curimatella lepidura (Characiformes, Curimatidae) from the Três Marias Reservoir, Brazil / Copépodes parasitos de Curimatella lepidura (Characiformes, Curimatidae) do reservatório de Três Marias, Brasil

Copépodes ergasilídeos coletados nas brânquias de Curimatella lepidura do reservatório de Três Marias, alto rio São Francisco, Minas Gerais, Brasil e identificados como Miracetyma etimaruya e Ergasilus sp., constituem o primeiro registro de parasitos nesse peixe forrageiro e endêmico. A ocorrência foi independente do sexo e do tamanho dos peixes. A distribuição geográfica conhecida das espécies de Miracetyma Malta, 1993, restrita à bacia do rio Amazonas, é ampliada neste estudo para a bacia do rio São Francisco.

Parasitic community of Fransciscodoras marmoratus (Reinhardt, 1874) (Pisces: Siluriformes, Doradidae) from the upper São Francisco river, Brazil / Comunidade parasitária de Franciscodoras marmoratus (Reinhardt, 1874), (Pisces: Siluriformes, Doradidae) do alto rio São Francisco, Brasil

One hundred and thirteen specimens of Franciscodoras marmoratus (Reinhardt, 1874) were collected in the upper São Francisco River (18° 12' 32" S, 45° 15' 41" W, state of Minas Gerais) between September, 1999 and January, 2004 to investigate their parasite fauna. From this total, 45 (39.8 percent) were afflicted by at least one parasite species. The parasitic richness consisted of six species represented by Hirudinea (n = 20), Monogenoidea (n = 25), Eucestoda (n = 55), Nematoda (n = 1, n = 2) and Acanthocephala (n = 41) found in the dry and wet periods making a total of 144 specimens. Proteocephalus renaudi Chambrier & Vaucher, 1994 was the only species with prevalence higher than 10 percent and a typical aggregate distribution pattern. The prevalence, intensity and abundance of P. renaudi were not influenced by the total length or sex of the hosts or by the collection periods. The relative condition factor indicated that the health of the P. renaudi hosts was not significantly affected in relation to fish not infected by parasites. The fish stocked in tanks before necropsy were opportunistically infested by Lernaea cyprinacea Yashuv, 1959. The various parasites found indicate that F. marmoratus is omnivorous and a potential definitive host. The parasite species, except for Acanthocephala, have expanded their known geographic distribution to the São Francisco River Basin. The parasite community was considered isolationist because of the low endoparasite diversity, infrapopulations with low intensity, lack of evidence of parasite interactions and sparse signs of parasite aggression against their hosts.

Cento e treze espécimes de Franciscodoras marmoratus (Reinhardt, 1874) foram coletados no alto São Francisco (18° 12' 32" S, 45° 15' 41" W, Estado de Minas Gerais), entre setembro de 1999 e janeiro de 2004, para a investigação de sua parasitofauna. Desse total 45 (39,8 por cento) estavam parasitados por, pelo menos, uma espécie de parasito. A riqueza parasitária foi constituída por seis espécies representantes de Hirudinea (n = 20), Monogenoidea (n = 25), Eucestoda (n = 55), Nematoda (n = 1, n = 2) e Acanthocephala (n = 41), encontradas nos períodos da seca e da cheia, que totalizaram 144 espécimes. Proteocephalus renaudi Chambrier & Vaucher, 1994 foi a única espécie com prevalência superior a 10 por cento, com típico padrão de distribuição agregado. A prevalência, intensidade e a abundância parasitária de P. renaudi não foram influenciadas pelo comprimento total e sexo dos hospedeiros e nem pelos períodos de coleta, respectivamente. O fator de condição relativo indicou que os hospedeiros de P. renaudi não tiveram higidez significativamente afetada em relação aos peixes não parasitados. Os peixes estocados em tanques, antes das necropsias, foram oportunistamente infestados por Lernaea cyprinacea Yashuv, 1959. Os diversos parasitos encontrados indicam F. marmoratus onívoro e potencial hospedeiro definitivo. As espécies de parasitos, com exceção de Acanthocephala, têm ampliada sua distribuição geográfica conhecida para a bacia do rio São Francisco. A comunidade parasitária foi considerada isolacionista devido à baixa diversidade endoparasitária, infrapopulações com baixa intensidade, interações parasitárias não evidentes e raros sinais de agressões dos parasitos contra seus hospedeiros.

Ethnoecology and conservation in protected natural areas: incorporating local knowledge in Superagui National Park management

Grande parte das unidades de conservação no Brasil foi criada nos espaços litorâneos, habitados secularmente por populações humanas, por isso surgiu uma série de conflitos envolvendo a permanência dessas populações nessas áreas protegidas. Buscando solucionar parte desses problemas, estudos etnoecológicos vêm sendo desenvolvidos visando a resgatar o conhecimento que as comunidades humanas locais têm sobre o ambiente terrestre, os ciclos naturais, a ocorrência e a abundância de espécies animais, bem como os usos e valores a eles atribuídos. O resgate e a valorização desse conhecimento aliados ao levantamento das problemáticas que estão interferindo negativamente na qualidade de vida, como também de meios e alternativas para solucioná-las, são instrumentos úteis no planejamento e no manejo de uma unidade de conservação. Assim, este estudo propõe uma educação ambiental baseada em métodos etnocientíficos como mediadora de um diálogo que vise à manutenção da sociodiversidade da região abrangida pelo Parque Nacional do Superagui.

IgA response in serum and gut secretion in sensitized mice fed with the dust mite Dermatophagoides pteronyssinus extract

Induced oral tolerance to mucosal-exposed antigens in immunized animals is of particular interest for the development of immunotherapeutic approaches to human allergic diseases. This is a unique feature of mucosal surfaces which represent the main contact interface with the external environment. However, the influence of oral tolerance on specific and natural polyreactive IgA antibodies, the major defense mechanism of the mucosa, is unknown. We have shown that oral administration of an extract of the dust mite Dermatophagoides pteronyssinus (Dp) to primed mice caused down-regulation of IgE responses and an increase in tumor growth factor-á secretion. In the present study, we observed that primed inbred female A/Sn mice (8 to 10 weeks old) fed by gavage a total weight of 1.0-mg Dp extract on the 6th, 7th and 8th days post-immunization presented normal secretion of IL-4 and IL-10 in gut-associated lymphoid tissue and a decreased production of interferon gamma induced by Dp in the draining lymph nodes (13,340 ñ 3,519 vs 29,280 ñ 2,971 pg/ml). Mice fed the Dp extract also showed higher levels of serum anti-Dp IgA antibodies and an increase of IgA-secreting cells in mesenteric lymph nodes (N = 10), reflecting an increase in total fecal IgA antibodies (N = 10). The levels of secretory anti-Dp IgA antibodies increased after re-immunization regardless of Dp extract feeding. Oral tolerance did not interfere with serum or secretory IgA antibody reactivity related to self and non-self antigens. These results suggest that induction of oral tolerance to a Dp extract in sensitized mice triggered different regulatory mechanisms which inhibited the IgE response and stimulated systemic and secretory IgA responses, preserving the natural polyreactive IgA antibody production.

Induction of oral tolerance and the effect of interleukin-4 on murine skin allograft rejection

We studied the effect of oral and portal vein administration of alloantigens on mouse skin allograft survival. Graft receptor BALB/c mice received spleen cells (30, 90, 150 or 375 x 10(6)) from donor C57BL/6 mice intragastrically on three successive days, starting seven days before the skin graft. Allograft survival was significantly increased with the feeding of 150 x 10(6) allogeneic spleen cells by one gavage (median survival of 12 vs 14 days, P <= 0.005) or when 300 x 10(6) cells were given in six gavage (12 vs 14 days, P < 0.04). A similar effect was observed when 150 x 10(6) spleen cells were injected into the portal vein (12 vs 14 days, P <= 0.03). Furthermore, prolonged allograft survival was observed with subcutaneous (12 vs 16 days, P <= 0.002) or systemic (12 vs 15 days, P <= 0.016) application of murine interleukin-4 (IL-4), alone or in combination with spleen cell injection into the portal vein (12 vs 18 days, P <= 0.0018). Taken together, these results showed that tolerance induction with spleen cells expressing fully incompatible antigens by oral administration or intraportal injection partially down-modulates skin allograft rejection. Furthermore, these findings demonstrated for the first time the effect of subcutaneous or systemic IL-4 application on allograft skin survival suggesting its use as a beneficial support therapy in combination with a tolerance induction protocol.

Cysticercosis/taeniasis: recent advances in serological and molecular diagnoses.

Serodiagnosis by immunoblot, using recombinant chimeric T. solium antigen and native glycoprotein antigens, has been applied for neurocysticercosis cases. Specific antibodies against both antigens were detected in serum samples from NCC patients involving multiple cysts in the brain, whereas it was not always easy to detect specific antibodies in NCC cases with a solitary cyst or calcified lesion(s). On the other hand, the diagnosis for human taeniasis or worm carriers has been routinely performed by stool examination. In this study, multiplex PCR has been established to differentiate taeniasis using Taenia mitochondrial DNA in fecal samples from worm carriers. Furthermore, the molecular identification of human taeniid cestodes by base excision sequence scanning thymine-base analysis has also been introduced. This method provides four thymine-base peak profiles unique for Asian and American/African genotypes of T. solium, T. saginata and T. asiatica. By comparing thymine base peak profiles, it is possible to differentiate human taeniid cestodes without DNA sequencing. The approaches are powerful tools for the routine diagnosis of taeniasis and the molecular identification of taeniid cestodes.

Desenvolvimento de forma farmacêutica líquida de uso oral, isenta de substâncias glicogênicas, com extrato fluido de Mikania glomerata Sprengel - Asteraceae (guaco)

Mikania glomerata Sprengel, Asteraceae (guaco) é tradicionalmente empregado como expectorante na forma de infusão, extrato fluido, tintura e xarope. Este trabalho teve como objetivo o desenvolvimento de uma forma farmacêutica líquida, isenta de substâncias glicogênicas, veiculando o extrato fluido desta, como substituto do xarope de guaco para pessoas, que por alguma restrição não possam ingerir sacarose ou açúcar invertido, componente dos xaropes em geral. Desenvolveu-se uma formulação líquida, definindo-se as concentrações de conservantes, agentes umectantes, edulcorantes e flavorizantes, testaram-se polímeros, espessantes usuais em processos tecnológicos, para reproduzir a viscosidade fornecida pelos xaropes. Analisou-se o comportamento reológico e uma avaliação preliminar das características físicas do produto. Dos polímeros testados, o alginato de sódio (1 por cento) foi o que apresentou melhores resultados frente aos parâmetros analisados, com comportamento reológico semelhante ao dos fluidos Newtonianos, e pH adequado ao uso oral, além da compatibilidade frente ao extrato fluido de guaco.

Mikania glomerata Sprengel, Asteraceae (guaco), is traditionally used against cough as an infusion, a fluid-extract, a tincture or a syrup. The present investigation had as objective the development of a sugarless pharmaceutical liquid form to carry the guaco fluid extract, a substitute to the guaco syrup, it would specially help those who cannot ingest the glycogenic substances found in syrups. Liquid formulation was developed, in which the preservants concentration, the humectants agents, and sweeteners and flavors were defined, thickening polymers commonly used in technological processes in order to reduce the syrups viscosity were tested. The rheological behavior was analyzed and the preliminary evaluation of physical characteristic was done. Of all the tested polymers, the sodium alginate (1 percent) showed itself the most stable, regarding the analyzed parameters. It had a rheological behavior similar to the Newtonian fluids and has adequate pH of oral use, as well as compatibility to the fluid guaco extract.

Environmental education praxis toward a natural conservation area

A non-formal Environmental Education (EE) Program has been implemented in the natural conservation area (Ecological Station of Jataí, Luiz Antônio, São Paulo State), through (EE) paradigms, which consider the objectives of education about, in and for the environment within cultural and natural perspectives. The aim of this Program is to support information and scientific knowledge to provide opportunities to the local population to be aware of environmental impacts and risks resulting from the soil use that threaten the environmental quality and the biodiversity of the Ecological Station of Jataí. The Program understands that the promotion of community empowerment could bring the sense of participation and the directives to management for decision-making for local sustainability. The model was projected on local reality, but considering the global issues of environmental paradigms. The environmental characterization (biophysical components) through a Geographical Information Systems was related to the hydrographic basin analysis. The environmental perception was utilized as a main tool to analyse population understanding of local environment, and (EE) pedagogical tools were produced to promote environmental awareness. Since the ecological dimension of (EE) was the main approach, the programme intends to assemble the cultural perspective, achieving the global view of (EE)

Analise de mediadores pro-inflamatorios na resposta alergica a antigenos de acaro de poeira domestica em camundongos / Pro-inflamatory mediators analisys in the alergic response to mite antigens of domestic dust in rats

Ha um grande contigente de pacientes com rinite alergica na populacao que nao se beneficiam com os tratamentos convencionais, tornando seu tratamento um desafio para o corpo clinico. A fim de descrever os mecanismos imunes e inflamatorios que envolvem o pulmao na broncoprovocacao por Dhermatophagoides pteronyssinus, o presente estudo utilizou de metodos de citometria de fluxo, cultura de celulas e e contagem total e diferencial de celulas e dosagem de NO para a analise do lavado bronco alveolar...

Antagonism of clonidine injected intracerebroventricularly in different models of salt intake

Clonidine, and alpha2-adrenergic agonist, injected into the brain inhibits salt intake of animals treated by the diuretic model of sodium depletion. In the present study, we address the question of whether central injection of clonidine also inhibits salt intake in animals deprived of water or in the need-free state. Saline or clonidine (30 nmol) was injected into the anterior third ventricle of 24-h sodium-depleted (furosemide + removal of ambient sodium), of 24-h water-deprived and of normovolemic (need-free state) adult male rats. Clonidine injected intracerebroventricularly (icv) inhibited the 1.5 per cent NaCl intake for 120 min by 50 to 90 per cent in every model tested. Therefore, different models of salt intake are inhibited by icv injection of clonidine. Idazoxan, an alpha2-adrenergic antagonist, injected icv at a dose of 160 nmol, inhibited the effect of clonidine only in the furosemide + removal of ambient sodium model of salt intake. This indicates that the antagonism of this effect by idazoxan is dependent on the body fluid/sodium status of the animal.

Inhibitory effects of cimetidine on graft survival of allotransplanted rats submitted to an active-passive enhancement protocol

The objetive of the presented study was to determine wheter cimetidine, a type-2 histamine receptor antagonist, inhibits the immunological enhancement of allografted rats achieved by treatment with donor antigen plus anti-donor antibody. Groups of rats submitted to this active-passive enhancement protocol and treated ip with 30 (APEC30; Group I; N = 4) or 60 (APEC 60; Group II; N = 8) mg/day cimetidine for 14 days had a significantly shorter graft survival (20.2 ñ 5.1 and 11.1 ñ 2.6 days, respectively) than the control group (animals submitted to the enhancement protocol and killed on day 72 after transplant when the graft was beating normally; APE; Group III; N = 6; P<0.05). On the other hand, these animals had a significantly longer graft survival than rats allotransplanted but not treated for enhancement (ALLO; Group V; N = 5; 8.2 ñ 0.8 days). The surgical control, consisting of isotransplanted animals, had a long-term survival (ISO; Group V; N = 6; rats killed 120 days after transplant with the graft beating normally). Animals treated with cimetidine, but not submitted to the enhancement protocol (AC 60; Group IV, N = 4) had a significantly shorter graft survival (6.25 ñ 0.5) than the allotransplanted animals (Group V). These results indicate inhibition of the suppressor mechanisms which participate in this type of immunological enhancement

Immunomodulatory effect of cimetidine on the proliferative responses of splenocytes from T. cruzi-infected rats

O efeito imunomodulatorio da Cimetidine (CIM), um antagonista do receptor de histamina-tipo 2, foi avaliado na resposta blastogenica a Con A em celulas de ratos Wistar Furth (WF) infectados pela cepa Y de Trypanosoma cruzi (T.cruzi). Foi observado que apenas na concentracao de "10 POT. -3"M de Cimetidine houve amplificacao da resposta blastogenica de esplenocitos normais a Con A. Entretanto, a capacidade mitogenica de esplenocitos de animais infectados foi restaurada na presenca de molaridades da droga que variaram entre "10 POT. -8" a "10 POT. -3". Os resultados demonstraram que a CIM tem o potencial de modular a resposta mitogenica de celulas de animais infectados pelo T.cruzi, sugerindo um papel imunoregulatorio da histamina e/ou celulas que expressam receptores H2 nesta infeccao.

In vitro action of some disinfectants on Paracoccidioides brasiliensis yeast forms

Descreveu-se a acao fungicida do hipoclorito de sodio (0,3; 1; 2,5; 5 e 10 por cento); do formaldeido (em solucao aquosa a 2,5 e 10 por cento); e alcool etilico a 70,0 por cento sobre formas leveduriformes de 2 cepas de Paraccoccidioides brasiliensis: Pb 18 e cepa Goiana, recentemente isolada. A incubacao do fungo e desinfetantes foi realizada a temperatura ambiente por periodos de 1, 2, 24, 48 e 72 horas. A viabilidade foi avaliada pelo tratamento com diacetato de fluoresceina-brometo de etideo; pela cultura em meios solidos e liquidos a 36 graus Celsius e 26 graus Celsius; transformacao de levedura em micelio a temperatura ambiente; e estudo radiometrico da atividade metabolica. Todas as concentracoes de todos os desinfetantes estudados foram capazes de inativar ambas as cepas, exceto na incubacao com formaldeido a 2 por cento por 1 hora, em que o tratamento por diacetato de fluoresceina-brometo de etideo revelou 40 por cento e 27 por cento de celulas viaveis, respectivamente, para a cepa Pb 18 e Goiana. A transformacao de levedura em micelio foi considerada um metodo rapido, com resultados semelhantes ao cultivo em meios solidos e liquidos.

Evaluation of the genotoxic activity and acute toxicity of Euphorbia splendens latex, a molluscicide for the control of Schistosomiasis

The latex of euphorbia splendens var. hislopii has a molluscicidal action at low concentration (LD90 less than 1.5 ppm or 1.5 */ml) against the vector snails of schistosomiasis. In the present study, the latex in natura or after lyophilization was submitted to the Ames test and the chromotest to evaluate genotoxicity, to the Microtox System to determine acute toxicity, and to the Chinese hamster ovary cell assay (CHO) to measure cytotoxicity. The latex had no mutagenic activity in the presence or absence of S9 toward the TA98 and TA100 strains of Salmonella typhimurium (Ames test) at concentration up to 200 */plate (in natura) and of 200 *g/plate (lyophilized). The lyophilized latex had no genotoxic activity (Chromotest) and acute toxic effect on Photobacterium phosphoreum at concentrations up to 445 *g/ml, whereas the sample in natura had a toxic effect with an EC50 of 148,000 *l/l (or ppm). In the CHO/cytotoxicity assay, the lyophilized latex had no cytotoxicit effect in quantities up to 200 *g. The latex was found to have no acute toxicity or mutagenic at the concentrations of 10 to 12 *g/ml (or ppm) that are being proposed for molluscicidal use in the field