Efecto de distintos esquemas de administración de ciclofosfamida en la mortalidad del ratón adulto infectado con virus Junín / [Effect of various schedules of cyclophosphamide administration on the mortality of the adult mouse infected with Junín virus]

The object of this paper was to determine the influence of cyclophosphamide immunosuppression on the mortality of 40-45 day old Balb/c mice infected intracerebrally with a pathogenic strain of Junin virus, using different administration schedules. Up to 200 mg/kg of cyclophosphamide were not toxic. Results show that, unlike in other experimental models, three or four 50 mg/kg cyclophosphamide doses given both before and after viral infection were required to break-down resistance to Junin virus (90-96.5

in controls). Taking into account the effect of cyclophosphamide on the cell populations involved in the immune response, causes likely to lead to the greater susceptibility of the suppressed adult mouse to Junin virus are discussed.

Infección de primates del nuevo mundo con virus Junín. IV. Aotus trivirgatus / [Infection of New World primates with Junín virus. IV. Aotus trivirgatus]

Owl monkeys (Aotus trivirgatus) were inoculated with XJ, a pathogenic strain of Junin virus, seeking new animal models for Argentine Hemorrhagic Fever. Nine monkeys were inoculated intramuscularly with 30 or 300,000 TCID50 of junin virus. Hematological and virological studies showed no alteration in blood elements such as red cell, reticular cell and platelets, up to 28 days after inoculation. Hemoglobin and hematocrit determinations also remained constant. However, significant neutropenia was seen at day 11 and minimal viremia was detected in some animals during the second and third week post-inoculation. No clinical or behavioral modifications were observed during the eighty-days observation period. Non-specific necropsy findings included pyelonephritis, pneumonitis, liver abscess and eosinophilic spleen infiltrate. All of these findings seem to be unrelated to Junin virus inoculation. No virus was present in organs of animals killed 29, 57 or 85 days post-inoculation. All nine owl monkeys developed serum neutralizing antibodies by day 22. It is concluded that the owl monkey suffers a subclinical infection when inoculated with Junin virus, similar to that seen in other primate species (Saimiri sciureus and Alouatta caraya).

Infeccion de primates del Nuevo Mundo con virus Junin: III Saimiri sciureus / Infection of New World primates with Junin virus. III Saimiri sciureus

Cuatro primates neotropicales de la especie S. sciureus fueron inoculados con la cepa patogena prototipo XJ del virus Junin a fin de determinar su susceptibilidad a la misma. Dos S. sciureus fueron inoculados por via intramuscular con 10(3) DL50 de dicha cepa, y las dos restantes con 10 (5) DL50. Independentemiente de las dosis de virus administrada, ninguno de los monos inoculados mostro signos clinicos de enfermedad hasta la fecha en que se los sacrifico (entre 82 y 178 dias despues de la infeccion), para realizar estudios histologicos y de persistencia viral. No se detectaron modificaciones significativas en el numero de hematies, reticulocitos, plaquetas y leucocitos. La busqueda de virus en sangre entre los 7 y 36 dias despues de la infeccion, dio resultados negativos. Tampoco se detecto la presencia de virus infeccioso, de antigeno viral o de modificaciones histologicas, en los organos de los animales sacrificados. Tres de los 4 monos infectados desarrollaron anticuerpos neutralizantes humorales antivirus Junin