RESUMO
Andropogon is a pantropical grass genus comprising 100-120 species and found mainly in the grasslands of Africa and the Americas. While the genomic relationships between many Andropogon species have been resolved by studying chromosome behavior in interspecific hybrids, relationships between the North and South American diploids have remained elusive. Further, the genome composition of two hexaploid species (including the important forage grass Andropogon lateralis Nees) has been unclear because of the strong hybridization barriers that exist between species. Consequently, genomic in situ hybridization was applied to shed light on these issues. The results confirmed that (i) both the South American (Andropogon selloanus (Hack.) Hack., Andropogon macrothrix Trin.) and North American (Andropogon gyrans Michx.) diploid species shared a common S genome and (ii) the S genome comprises just one of the three genomes in the hexaploids A. lateralis Nees and Andropogon bicornis L. The evolutionary and taxonomic implications of these findings are discussed.
Assuntos
Genoma , Poaceae/genética , Cromossomos/ultraestrutura , DNA/química , Primers do DNA/química , Diploide , Variação Genética , Genoma de Planta , Hibridização In Situ , Microscopia de Fluorescência , Hibridização de Ácido Nucleico , Ploidias , Ribossomos/ultraestruturaRESUMO
BACKGROUND: Little is known about factors determining the pathogenesis and severity of asthma in Latin American countries. Costa Rica, one of the most prosperous Latin American nations, has a very high asthma prevalence. OBJECTIVE: To examine the relation between potential risk factors and childhood asthma in Costa Rica. METHODS: Cross-sectional study of 214 schoolchildren aged 10 to 13 years participating in phase II of the International Study of Asthma and Allergies in Childhood. RESULTS: After adjustment for age, gender, area of residence, maternal smoking during pregnancy, and airway responsiveness to hypertonic saline solution, sensitization to house dust mites was associated with asthma (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.1 to 4.4; p = 0.02). In the multivariate analysis, parental education no higher than high school (OR, 3.0; 95% CI, 1.4 to 6.4; p < 0.01) and parental history of asthma (OR, 2.6; 95% CI, 1.3 to 5.2; p < 0.01) were also independent predictors of childhood asthma. CONCLUSIONS: Sensitization to house dust mites, low parental education, and parental history of asthma are associated with asthma in Costa Rica.
Assuntos
Asma/epidemiologia , Adolescente , Animais , Asma/genética , Criança , Costa Rica/epidemiologia , Estudos Transversais , Escolaridade , Humanos , Ácaros , Análise Multivariada , Fatores de RiscoRESUMO
Previous studies of schoolchildren in Costa Rica have shown an asthma prevalence of 23% and a high level of sensitization, particularly to mite allergens. As a continuation of these studies, some 400 dust samples were collected from various places in Costa Rica, and parts of these were analyzed for specific mite and cockroach allergens, as well as for the number of mites and amount of guanine. Guanine was quantified by a diazo, as well as an HPLC method, which were found to be highly correlated. The concentrations of guanine by the diazo method, Der p 1, Der f 1, and the number of mites were higher in bed dust than in bedroom floor dust, and it was possible to quantify mite allergens and guanine in almost all bed-dust samples. The mean levels were 2-3 times higher than the proposed risk level for elicitation of symptoms in mite-sensitive asthmatics. Bed and bedroom floor dust contained more guanine and mite allergen in humid (> 2000 mm rain) than in drier places (P < 0.05), but the number of mites in bed and bedroom floor dust was higher in less humid places (P = 0.01). The guanine content in bedroom floor dust was higher in areas with a temperate climate than in areas with a warmer climate (P < 0.001, Bartlett's chi square [BCS]), as was the number of mites (P < 0.01, Kruskal-Wallis [KW], 0.04, BCS) and the Der p 1 concentration (P = 0.01, BCS; P = 0.02, KW). The Der f 1 concentration in bedroom floor dust was higher in a warmer than in a temperate climate (P < 0.001, BCS). More guanine and mites were found in urban than in rural bed dust (P = 0.03, KW). Dust samples from the metropolitan area (temperate climate) of Costa Rica contained higher levels of guanine (P < 0.01) and Der p 1 (P = 0.07) than the coastal areas, but very little Der f 1. In these samples, guanine and Der p 1 allergen were closely related, and 2 micrograms of the allergen was equivalent to 0.49 mg of guanine. Two-thirds of bed and floor samples collected on cotton filters contained Bla g 2 allergen at mean levels of 1.6 and 2.1 units/g dust, respectively. Cockroach allergen was, however, absent in all bed samples from the metropolitan area, but did occur in very high concentrations in the coastal bed dust samples collected with tighter polyester filters. In conclusion, the concentration of guanine and Der p 1 was very high in the bed dust of Costa Rican homes. Some factors, such as humidity, small houses for large families, and type of bedding, probably favored the heavy mite infestation, which is probably related to the widespread occurrence of bronchial asthma in this country.
Assuntos
Alérgenos/análise , Baratas/imunologia , Guanina/imunologia , Habitação , Ácaros/imunologia , Animais , Roupas de Cama, Mesa e Banho , Clima , Costa Rica , Poeira , GeografiaRESUMO
The prevalence of asthma among schoolchildren in Costa Rica is very high -- at the level of 20-30% -- and the reason is still unknown. A group of children from our previous epidemiologic study was randomly selected in order to establish the relation between asthma symptoms and allergy sensitization to common allergens. Serum samples from children with and without asthma were analyzed for the presence of IgE antibodies to 36 different allergens, for the presence of IgE antibodies to a pool of 10 common allergens, and for total serum IgE. The most prevalent IgE antibodies were those to mite, cockroach, dog, and house-dust allergens with MAST pipettes for the serologic measurements. Positive reactions to house dust, mite, cat, and the two molds (Alternaria and Cladosporium), and food allergens such as egg white, peanut, and shellfish were significantly more prevalent among the asthmatics than the nonasthmatics. Sensitization was equally prevalent at different ages, but the house-dust, mite, cat, dog, cockroach, Alternaria, and egg-white allergens had sensitized boys more often than girls (P < 0.01). The result of the analysis of IgE antibodies to a pool of 10 common allergens by Phadiatop supported the MAST pipette results, showing allergen sensitization in 57.7% of the asthmatic children and 42.3% in the nonasthmatic group. The concentration of IgE was significantly higher among the asthmatic children (372.2 kU/l) than among the nonasthmatic children (249.1 kU/l) (P < 0.00001). Parasitic infestations were not examined in this study, but in most of Costa Rica these have largely been eliminated and could not explain the high total IgE levels. Our data indicate that the very high prevalence of bronchial asthma in Costa Rican schoolchildren can be related to sensitization, especially to airborne indoor allergens such as those of mites, cockroaches, and dogs.
Assuntos
Alérgenos/imunologia , Asma/imunologia , Imunização , Alérgenos/análise , Animais , Anticorpos/análise , Gatos/imunologia , Criança , Baratas/imunologia , Costa Rica , Cães/imunologia , Poeira/análise , Feminino , Hipersensibilidade Alimentar/imunologia , Humanos , Imunoglobulina E/análise , Masculino , Ácaros/imunologia , Valores de Referência , Instituições AcadêmicasRESUMO
The ability of two antivenoms to Vipera spp., consisting of Fab (Therapeutic Antibodies), or of F(ab')2 (Zagreb Institute of Immunology) antibody fragments, to neutralize the hemorrhagic activity of Vipera berus snake venom in mice, was compared. First, the neutralizing potency was determined by in vitro preincubation of venom and antivenom, followed by intradermal injection into mice and subsequent measurement of the hemorrhagic area. Both antivenoms had the same anti-hemorrhagic potency, in terms of volume of antivenom/mass of venom, with an estimated ED50 (50% reduction of the effect) of 80 microliters antivenom/mg venom. Therefore, no adjustments in dose were necessary for subsequent in vivo comparative experiments. When the antivenoms were administered intravenously into mice immediately after intradermal venom injection, there was no difference in their effectiveness in reducing hemorrhagic lesions, at all doses tested. These results indicate that neutralization of local hemorrhagic activity of V. berus venom in vivo is not improved by the use of the smaller Fab fragments, in comparison to F(ab')2, when equivalent neutralizing units are injected. However, this does not exclude the possibility that other clinically relevant venom effects may be neutralized with different efficiency by Fab or F(ab')2 fragments of antibodies.
Assuntos
Antivenenos/uso terapêutico , Hemorragia/terapia , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Venenos de Víboras/toxicidade , Animais , Relação Dose-Resposta a Droga , Hemorragia/etiologia , Camundongos , ViperidaeRESUMO
The IgE immune response was studied in female athymic, nude (Lewis rnu/rnu) and euthymic (Lewis +/+) rats infected with the nematode Nippostrongylus brasiliensis. During the course of the infection, serum IgE levels were followed using an enzyme-linked immunosorbent assay technique (ELISA), while the surface expression and occupancy of IgE receptors on peritoneal mast cells were quantified using flow cytometry after immunolabelling with anti-IgE. The results show that the up-regulation of IgE receptors, which takes place on the mast cells of both athymic and normal rats during the early phase of the immune response, is more pronounced and longer-lasting in normal rats than in athymic ones, thereby suggesting that T cells are necessary for a full response to the parasite infection. The increased IgE occupancy observed on the mast cells during the early phase of the parasite immune response was not reflected in the serum IgE levels, which remained low during the entire infection period in athymic rats. In euthymic rats, on the other hand, there was a pronounced increase in serum IgE, as well as an increase in IgE occupancy on the mast cells, all reaching a peak level after 2 weeks of infection. However, there was no significant correlation between the serum IgE concentration and IgE occupancy or the density of IgE receptors on the mast cells of the individual euthymic rats. This indicates that the quantification of IgE occupancy on the mast cells may be a better way of detecting low-level IgE responses than the measurement of serum IgE. These findings, which were obtained in female Lewis rats, when compared with our previous findings in male rats of the same strain, suggest that sex differences may exist in terms of the intensity and duration of the IgE immune response to the parasite infection.
Assuntos
Imunoglobulina E/imunologia , Mastócitos/imunologia , Nippostrongylus , Infecções por Strongylida/imunologia , Linfócitos T/imunologia , Animais , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Imunoglobulina E/sangue , Ratos , Ratos Nus , Receptores de IgE/metabolismo , Infecções por Strongylida/sangueRESUMO
Avidities and titres of serum IgA, IgM, IgG, and salivary IgA antibodies for poliovirus type 3, beta-lactoglobulin and E. coli O antigens were analysed in well-nourished (n=58) and mildly to moderately undernourished (n = 18) 1-7-year-old children, living in slums in São Paulo, Brazil, with irregular water supply and no sewage system. The serum titres of antibodies in the undernourished children were not statistically different from the well-nourished ones, except for the IgA anti-beta-lactoglobulin titres which were lower in the youngest undernourished group. In respect to avidity of the serum antibodies, no statistical difference was observed, except that the youngest undernourished children presented avidities of serum IgA anti-E. coli O antigens higher than those of the well-nourished children of the same age range. With respect to salivary titres and avidities no difference was observed between well-nourished and undernourished children. The fact that the undernourished children were not deficient in antibody amount or quality, as measured in this study, suggests that in this respect their immune system was not impaired.
Assuntos
Anticorpos Antibacterianos/análise , Anticorpos Antivirais/análise , Transtornos da Nutrição Infantil/imunologia , Imunoglobulinas/análise , Lactoglobulinas/imunologia , Brasil , Criança , Pré-Escolar , Escherichia coli/imunologia , Humanos , Imunoglobulina A/análise , Imunoglobulina A/sangue , Imunoglobulina G/análise , Imunoglobulina G/sangue , Imunoglobulina M/análise , Imunoglobulina M/sangue , Imunoglobulinas/sangue , Lactente , Poliovirus/imunologia , Saliva/imunologiaAssuntos
Antígenos/imunologia , Microbiologia Ambiental , Fezes/química , Imunoglobulina A Secretora/análise , Mucosa Intestinal/imunologia , Distúrbios Nutricionais/imunologia , Saliva/imunologia , Proteínas e Peptídeos Salivares/análise , Urina/química , Fatores Etários , Afinidade de Anticorpos , Especificidade de Anticorpos , Brasil/epidemiologia , Criança , Pré-Escolar , Comorbidade , Exposição Ambiental , Escherichia coli/imunologia , Fezes/parasitologia , Humanos , Imunoglobulina A Secretora/imunologia , Lactente , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/parasitologia , Mucosa Intestinal/crescimento & desenvolvimento , Lactoglobulinas/imunologia , Distúrbios Nutricionais/epidemiologia , Distúrbios Nutricionais/metabolismo , Poliovirus/imunologia , Áreas de Pobreza , Fatores Socioeconômicos , População UrbanaAssuntos
Alimentos Fortificados , Imunoglobulina A Secretora/análise , Leite Humano/imunologia , Distúrbios Nutricionais/imunologia , Afinidade de Anticorpos , Infecções Bacterianas/etiologia , Infecções Bacterianas/prevenção & controle , Suscetibilidade a Doenças , Método Duplo-Cego , Ingestão de Energia , Escherichia coli/imunologia , Feminino , Guatemala/epidemiologia , Humanos , Imunoglobulina A Secretora/imunologia , Lactoferrina/análise , Distúrbios Nutricionais/dietoterapia , Distúrbios Nutricionais/epidemiologia , Antígenos O/imunologia , Gravidez , Toxoide Tetânico/imunologiaRESUMO
Thirty-one patients bitten by venomous snakes in Botucatu area (State of Säo Paulo - Brazil), sixteen by Bothrops spp. and fifteen by Crotalus durissus terrificus, were studied. The group comprised twenty-nine males and two females, ranging from fourteen to sixty-three years of age (mean 33 ñ 15.Leukocytosis with neutrophilia and lymphopenia, increase of mucoproteins and C reactive protein, decrease of total serum protein and albumin, were observed on the first day after the accident. In addition, increased serum levels of the cytokines IL-6 and IL-8, but not of IL-1 beta and TNF-alpha, were observed. The alterations were generally more intense in patients bitten by Crotalus durissus terrificus than by Bothrops spp. It is concluded that these snakebite envenomations closely resemble an acute trauma, inducing a typical acute-phase response.
Assuntos
Humanos , Masculino , Feminino , Citocinas/fisiologia , Elapidae , Interleucina-1/farmacologia , Interleucina-6/farmacologia , Leucocitose/fisiopatologia , Linfopenia/fisiopatologia , Proteína C-Reativa/farmacologia , Proteínas de Fase Aguda/farmacologia , Reação de Fase Aguda/fisiopatologia , Albumina Sérica/farmacologia , Interleucina-8/farmacologia , Mucoproteínas/farmacologia , Neutropenia/fisiopatologia , Mordeduras de Serpentes/fisiopatologia , Venenos de Serpentes/intoxicação , Fator de Necrose Tumoral alfaRESUMO
The prevalence of asthma in children between the ages of 5 and 17 years in Costa Rica was determined using a large sample (n = 2682). The definition of asthma was based on a combination of a physician's diagnosis and a symptom score, using information from a questionnaire given to the parents. An overall asthma prevalence as high as 23.4% was found. Sex, age, urban/rural location, or rain precipitation did not show any association with the diagnosis of asthma. The presence of smokers in the home was found to be an important risk factor (odds ratio = 1.6). Another identified risk factor was a high yearly average outside temperature, i.e. above 25 degrees C (odds ratio = 1.8). Furthermore, the proportion of children with more than four upper respiratory infections during the preceding year was found to be significantly increased in children with asthma (odds ratio = 4.3). The non-asthma group seemed to use equal amounts of drugs for the treatment of asthma as the asthma group. For a country like Costa Rica with limited economic resources the current work indicates two important issues for consideration in the future; firstly, to try to define the cause(s) of asthma and secondly, to continuously inform the physicians about the best way of diagnosing and treating asthmatic patients to ensure optimal handling of this large patient group.
Assuntos
Asma/epidemiologia , Adolescente , Criança , Pré-Escolar , Costa Rica/epidemiologia , Feminino , Temperatura Alta , Humanos , Masculino , Prevalência , Doenças Respiratórias/epidemiologia , Fatores de Risco , População Rural , Fumar/epidemiologia , Inquéritos e Questionários , População UrbanaRESUMO
The level and avidity indices of specific antibodies against tetanus toxoid, Escherichia coli O6 and a pool of 10 common E. coli O antigens, as well as the concentration and daily output of lactoferrin and total secretory IgA (SIgA), were evaluated in the milk of moderately undernourished mothers who were in a random blind design divided into two groups and given different caloric supplementations. Group A received a high caloric supplement (500 kcal/d), and group B received a low caloric supplement (140 kcal/d). Determinations were done using ELISA in various modifications, except for lactoferrin, which was quantified by single radial immunodiffusion. The avidity indices were investigated as an evaluation of the antibody quality. In all the parameters evaluated, the only difference found between the two groups at the end of the supplementation period was in the content of total SIgA, which was lower in group B, both in concentration and daily output. However, the SIgA remained within the normal range. Increases as well as decreases in the levels of specific IgA antibodies occurred within both groups. Avidity was decreased in group B only against one of the antigens tested. We conclude that moderate undernutrition does not impair the levels of milk antibodies, and supplementation does not enhance them but prevents the decrease in the content of total milk SIgA. There is a suggestion that the avidity of certain antibody specificities could be hampered.
Assuntos
Alimentos Fortificados , Imunoglobulina A Secretora/biossíntese , Leite Humano/imunologia , Distúrbios Nutricionais/dietoterapia , Distúrbios Nutricionais/imunologia , Anticorpos Antibacterianos/biossíntese , Afinidade de Anticorpos , Método Duplo-Cego , Ingestão de Energia , Escherichia coli/imunologia , Feminino , Guatemala , Humanos , Imunoglobulina A/biossíntese , Lactoferrina/metabolismo , Estudos Longitudinais , Leite Humano/metabolismo , Distúrbios Nutricionais/metabolismo , Toxoide Tetânico/imunologiaRESUMO
The levels of IgG, IgG subclasses, IgM and IgA were determined in serum from 17 patients with IgA deficiency and severe or frequent infections, allergy and/or autoimmunity (median age 7 years, range 2-19), 11 healthy IgA-deficient adults and 35 controls (median age 7 years, range 2-19). In serum from all groups IgG, IgM and IgA antibodies were determined against beta-lactoglobulin, E. coli O antigens and poliovirus type 1 antigen. In saliva of 15 IgA-deficient patients and 12 of the controls IgG, IgM and secretory component-carrying antibodies against E. coli O antigens and poliovirus type 1 were determined. The majority of the studied individuals lived under poor socio-economic conditions in Brazil, with consequent heavy microbial exposure. One IgA-deficient patient with rheumatoid arthritis also had IgG2 deficiency but no infectious problems. Four out of the 35 controls without any obvious infectious problems were found with IgA or IgG subclass deficiency. One of the 11 healthy IgA-deficient adults was low in the IgG2 subclass, one in IgG1 and one in IgG3. Those with symptomatic IgA deficiency had significantly higher serum IgG than the controls, especially in the age group 6-11 years. This latter group also had significantly increased serum IgG1 and IgG2 levels when compared with the age-matched controls. Salivary IgM antibodies to E. coli and poliovirus antigens were significantly higher among the symptomatic IgA-deficient individuals than among the controls. It is not clear at present whether these increased Ig levels are secondary to frequent infections and/or part of mechanisms that may compensate for the IgA deficiency.
Assuntos
Deficiência de IgA/epidemiologia , Deficiência de IgG/epidemiologia , Adolescente , Adulto , Antígenos de Bactérias/imunologia , Antígenos Virais/imunologia , Brasil , Criança , Pré-Escolar , Países em Desenvolvimento , Escherichia coli/imunologia , Feminino , Humanos , Imunoglobulina M/imunologia , Lactoglobulinas/imunologia , Masculino , Poliovirus/imunologia , PobrezaAssuntos
Humanos , Recém-Nascido , Lactente , Formação de Anticorpos , Aleitamento Materno , Leite Humano , Nutrição do LactenteAssuntos
Anticorpos/análise , Aleitamento Materno , Países em Desenvolvimento , Imunidade Materno-Adquirida , Leite Humano/imunologia , Coeficiente de Natalidade , Aleitamento Materno/estatística & dados numéricos , Pré-Escolar , Costa Rica/epidemiologia , Diarreia Infantil/etiologia , Diarreia Infantil/prevenção & controle , Europa (Continente) , Feminino , Contaminação de Alimentos , Guatemala/epidemiologia , História do Século XIX , História do Século XX , História Antiga , Humanos , Lactente , Alimentos Infantis/história , Mortalidade Infantil , Recém-Nascido , Infecções/epidemiologia , Paquistão/epidemiologia , Gravidez , Estudos Prospectivos , Estações do Ano , VacinaçãoRESUMO
Stability of virulence in P. brasiliensis isolates was studied with respect to the in vitro culture history and methods used for storage. Virulence in yeast-form P. brasiliensis isolates was tested in a chronic pulmonary murine model of paracoccidiodomycosis where progression of disease was quantitated in terms of colony forming units recoverable from lungs. Four isolates of P. brasiliensis, including recently isolated form patients or experimental animals, caused chronic progressive disease. Two isolates with a history of subculturing showed attenuation by causing resolving but chronic disease. An attenuated isolate became avirulent subsequent to 15 more years of subculturing. These findings suggest that virulence of P. brasiliensis can be attenuated or lost subsequent to cycles of subculturing over long periods. Our data suggest that the use of fresh P. brasiliensis isolates may be needed to provide reproducible virulence for experimental systems.
Assuntos
Pneumopatias Fúngicas/microbiologia , Fungos Mitospóricos/patogenicidade , Paracoccidioides/patogenicidade , Paracoccidioidomicose/microbiologia , Animais , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Inoculações Seriadas , Organismos Livres de Patógenos Específicos , VirulênciaRESUMO
The effect of coculturing yeast-form Paracoccidioides brasiliensis with murine cells was studied. Coculture of resident peritoneal or pulmonary macrophages with P. brasiliensis for 72 h dramatically enhanced fungal multiplication 19.3 +/- 2.4- and 4.7 +/- 0.8-fold, respectively, compared with cocultures with lymph node cells or complete tissue culture medium alone. Support of P. brasiliensis multiplication by resident peritoneal macrophages was macrophage dose dependent. Lysates of macrophages, supernatants from macrophage cultures, or McVeigh-Morton broth, like complete tissue culture medium, did not support multiplication of P. brasiliensis in 72-h cultures. Time course microscopic studies of cocultures in slide wells showed that macrophages ingested P. brasiliensis cells and that the ingested cells multiplied intracellularly. In sharp contrast to resident macrophages, lymphokine-activated peritoneal and pulmonary macrophages not only prevented multiplication but reduced inoculum CFU by 96 and 100%, respectively, in 72 h. Microscopic studies confirmed killing and digestion of P. brasiliensis ingested by activated macrophages in 48 h. These findings indicate that resident macrophages are permissive for intracellular multiplication of P. brasiliensis and that this could be a factor in pathogenicity. By contrast, activated macrophages are fungicidal for P. brasiliensis.
Assuntos
Citotoxicidade Imunológica , Ativação de Macrófagos , Macrófagos/parasitologia , Fungos Mitospóricos/crescimento & desenvolvimento , Paracoccidioides/crescimento & desenvolvimento , Fagocitose , Animais , Fracionamento Celular , Sistema Livre de Células , Células Cultivadas , Meios de Cultura , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Paracoccidioides/imunologia , Cavidade Peritoneal , Alvéolos PulmonaresAssuntos
Proteção da Criança , Prêmio Nobel , Criança , Costa Rica , História do Século XX , HumanosRESUMO
The fungicidal capacity of murine pulmonary macrophages (PuM) activated in vitro with IFN or lymphokines or in vivo with IFN was studied. PuM treated overnight with IFN (1000 U/ml), Con A-stimulated spleen cell culture supernatants, or lymph node cells plus Con A significantly killed yeast cells of the Gar w isolate of Paracoccidioides brasiliensis 45.5 +/- 2.1%, 72.0 +/- 4.2%, and 51.5 +/- 0.7% respectively. Two other isolates of P. brasiliensis (Ru and LA) were also killed (45 and 34%) by PuM activated by lymph node cells plus Con A. Control PuM had lesser but significant capacity for killing of P. brasiliensis isolates, ranging from 15 to 22%. Killing of P. brasiliensis by PuM activated by Con A-stimulated spleen cell culture supernatants could not be significantly inhibited by superoxide dismutase, catalase, or azide. When mice were treated in vivo with 4 X 10(5) IFN U i.p. and PuM isolated 24 h later, the PuM had significantly enhanced ability to kill P. brasiliensis (47.0 +/- 6.3%) compared with PuM from control mice (25.0 +/- 4.2%). PuM thus activated also showed enhanced killing (43%) of a second isolate compared with control PuM (22%). PuM from IFN-treated mice were able to significantly kill Blastomyces dermatitidis (37.5 +/- 0.7%) compared with control PuM (4.5 +/- 6.3%). These results show that PuM can be activated in vitro and in vivo by IFN for enhanced fungicidal activity against two pulmonary fungal pathogens and suggests that immunologic production of IFN could be an important factor in host defenses against these diseases.