ABSTRACT
The goal of this work was to develop in solid medium a fast method to obtain Paracoccidioides brasiliensis (Pb) with a high yield. Four culture media were assayed: Sabouraud honey-agar, Sabouraud dextrose-agar, tomato -agar-medium (TOM) and a medium based on grape pulp. The most exhuberant growth was observed in medium based on grape pulp. Antigen was prepared in microscale at 6, 10 and 15 days incubation of solid cultures and the crude product concentrated by means of Centriplus tubes (Helena, France). Isolated antigens were subjected to polyacrylamide gel electrophoresis, followed by immunolabelling and detection of the characteristic gp45 antigen employing human and Pb-infected rat sera. Best results were observed after 10 days culture in grape medium. None of the other three media afforded comparable results.
ABSTRACT
La paracoccidioidomicosis es una enfermedad endemica fungica ampliamente distribuida en Latino-America. La ciclofosfamida ha sido usada como potente imunosupresor para modular la respuesta inmune, en um modelo experimental infectado con Paracocidioides brasiliensis. Ratas macho buffalo/sim endocriadas de 250-300 gr. de peso, fueron inoculadas por via intracardiaca con 5.10 elevado a sexta potencia celalas de P. brasiliensis en fase levaduriforme...
Subject(s)
Animals , Male , Rats , Cyclophosphamide/therapeutic use , Immunity, Cellular/immunology , Paracoccidioidomycosis/therapy , Immunodiffusion , Paracoccidioides/classification , Paracoccidioidomycosis/immunologyABSTRACT
Entre julio 1988 y septiembre 1989, durante el período invernal, se investigó la presencia de Virus Sincicial Respiratorio (VSR) en 150niños menores de 5 años con infección respiratoria aguda (IRA) del tracto inferior (bronquiolitis: 56 por ciento; neumonías: 23 por ciento; bronquitis: 21 por ciento) por medio de un método rápido (inmunofluorescencia indirecta) sobre células del aspirado nasofaríngeo obtenido por succión con bomba de vacío. Se detectó antígeno de VSR en el 21,33 por ciento de los casos estudiados. El 25 por ciento de las bronquiolitis, el 17,6 por ciento de las neumonías y el 15,6 por ciento de las bronquitis resultaron positivas para VSR. La mayor frecuencia de positividad en bronquiolitis fue estadísticamente significativa (p<0,01). En neumonías se observó una disminución de la positividad a medida que aumentaba la edad. La distribución por grupo etáreo de los resultados positivos, independientemente del cuadro clínico, mostró una mayor frecuencia de VSR en menores de 23 meses. No se detectó diferencia significativa con respecto al sexo, estado nutricional y vacunación en pacientes con o sin VSR. En el grupo de 0-5 meses, el 42 por ciento de los casos positivos correspondió a menores de 30 días de vida. En 4/5 neonatos con VSR y en 3/12 menores de 12 meses con VSR se detectó la adquisición intrafamiliar de esta infección ya que se registró internación previa de hermanos con VSR en nuestro servicio. Se sugiere la necesidad de contar con métodos rápidos de estudio de la etiología viral en las IRAs a nivel hospitalario, lo que permitirá implementar estrategias más sólidas de control y tratamiento
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Bronchiolitis, Viral/etiology , Bronchiolitis/etiology , Bronchitis/etiology , Pneumonia, Viral/etiology , Pneumonia/etiology , Respiratory Syncytial Virus Infections/diagnosis , Respiratory Syncytial Virus, Human/isolation & purification , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique , Respiratory Syncytial Virus Infections/epidemiologyABSTRACT
The 2-day-old rat is known to be susceptible to infection by ip route with the XJ strain of Junin virus but resists inoculation with XJC13 strain (85
mortality). In order to determine whether peritoneal macrophages play a role in modulating the course of infection, viral replication in adherent peritoneal cells infected with either strain was studied. XJ was found to replicate 30-fold as regards XJC13 at day 3 pi. Besides, silica blockage of peritoneal macrophages was also evaluated. Following silica treatment, 60
survival was recorded for XJ-infected animals vs 15
for untreated infected controls. No significant differences were recorded for silica-treated XJC13-infected rats vs untreated infected controls. These preliminary findings indicate that, upon replication within the hosts macrophages at the peritoneal inoculation site, virus spreads readily to reach the target organs. Effective silica blockage lends support to this pathway, as shown by significantly greater survival in XJ-infected rats.
Subject(s)
Animals , Rats , Antibodies, Viral , Arenaviruses, New World , Hemorrhagic Fever, American , Antibody FormationABSTRACT
The susceptibility of the rat, infected at various ages by intraperitoneal route with the XJ prototype strain of Junin virus was studied two day-old animals showed maximum mortality, being the most suitable dose 10(3) LD50. Antiviral humoral response at 35 days pi was tested in survivors of all ages. Highest neutralizing antibody titers were found in those infected up to 4 days of age. This host behaves quite differently when infected by intracerebral route with the same XJ strain.